Investors want tech startups to use a “latest technology” to gain an “unfair advantage” allowing them to compete in an established market. This “unfair advantage” may be a reason that the investment is going to pay off. therefore startups may say that they are using (for instance) blockchain, AI and distributed systems and that it brings them a lot. The real reason startups can compete with established players is that they are small and efficient with a clear focus on what to build and no customers that slow them down. These things are also called “second-mover” advantages. But in my experience few startups dare to say they are using second mover advantages and are planning to win with better marketing and sales. ...

When you want to integrate the free Font Awesome icons in your application or website you are asked to “Enter your email to get started with a free Kit!” (source). It was always possible to just copy a single line in the head of your HTML. Fortunately this is still possible, this post will explain how. It will also show where to download the distribution for self hosting Font Awesome in your web site or web application. ...

In 2015 I was working on a Simple web framework for .NET. Back then I wanted to create an MVC framework that would allow me to run .NET web applications on Linux. Last year I ported the code .NET 5 (cross-platform now) and today I updated the code to support .NET 6. In this post I will show how to write a Visual Basic web application. Install .NET 6 on Ubuntu 22.04 If you are not on Windows and cannot install Visual Studio Community Edition 2022 then these instructions may be welcome to you. On Ubuntu 22.04 you need to execute: ...

For a mobile app I’m doing some front-end development and the design includes a lot of avatars. Unfortunately we don’t have any avatars of our users. Fortunately we do have their names and I’ve learned from Outlook and Trello that you can make great avatars with a user’s initials. In this post I show how to do this using PHP. Our goal The target is to create the following avatar with initials “MS” for my name “Maurits van der Schee”: ...

When your Symfony (PHP web framework) project uses AJAX requests and sessions (logging in) you may run into this 2012 bug where Symfony does not lock the session allowing for data loss on concurrent AJAX requests. I fixed the bug in 2014 in the SncRedisBundle, but that merge was reverted last year, creating an issue for some high traffic sites. In this post I propose a better solution for Symfony. Quick workaround The quick workaround is to use the NativeFileSessionHandler class, which uses the session storage (handler) in the php.ini (using session.save_handler and session.save_path) that does store session files on disk. As long as sessions are not working reliable (due to lack of locking) I advice to stay away from Symfony’s Redis and Memcache support for session storage and use this native variant (that does support locking). ...

I’ve written PHP-CRUD-API (3k Github stars) that lets you publish an instant REST API for an existing database. The latest version supports a mapping to allow you to clean up the names of your tables and columns. Other important features such as authentication and authorization were already supported. This recent addition makes the software better suited to publish a modern API on legacy systems (that run on MySQL, PostgreSQL or SQL Server). ...

Windows 10 professional supports full disk encryption with a PIN and a Trusted Platform Module (TPM) chip with it’s Bitlocker technology. If you don’t have (or believe in) TPM you can use either a pass-phrase or a USB startup key (file on a USB stick) to unlock your Bitlocker encrypted drive. When I apply full disk encryption on machines at the office it is to protect the data in case of computer theft. For machines that have a single user (me) I use a pass-phrase while for machines have multiple users I use a USB startup key. I carry the USB startup key on my key chain. Using a pass-phrase or USB startup key makes the confidentiality of the data on the system easier to understand and reason about, which attributes to real security. ...

Visual Studio Community 2022 is a very advanced IDE that has very good support for Visual Basic and the cross platform .NET 5. A C# programmer can choose to use Visual Studio Code, but that has no (language) support for Visual Basic. And since I was working on a Visual Basic application I was using Visual Studio Community as an IDE. This post explains the incompatibility between .NET 5 and a custom “Build Task” in Visual Studio Community’s build tool “MSBuild” (also applies to Visual Studio Professional). ...

I feel that using full disk encryption of laptops is a must. Not to protect against attacks with physical access (to the unencrypted boot loader or unprotected BIOS), but to avoid leaking data when the laptop is either lost or stolen. Entering a long passphrase is not very convenient, especially when you are sharing the device with multiple people. This post will explain how to unlock your computer by inserting a USB drive containing a key file, while still allowing to unlock using a passphrase. At the end of the post we describe how to conveniently hide the USB drive in Windows and Linux. ...

I feel that using full disk encryption of servers is a must. Not to protect against attacks with physical access (to the unencrypted boot loader or unprotected BIOS), but to avoid leaking data when a disk or computer is either stolen or replaced. But what do you do when you need to reboot your server and have no console access to enter the passphrase? This post will explain how to run a simple SSH server during the boot process to allow remote unlocking of the encrypted root partition. ...