java

Maintaining Checkstyle configs in a multi-repo project can be a chore. Let maven help you to create a global one.

This was originally posted as an answer to the question “How to convert a byte array to a hex string in Java?” on stackoverflow.com.

A simple script exporting chats from a rocket chat instance using the public REST API. Useful if no administrative access is possible.

This was originally posted as an answer to the question “Spring WebFlux differences when Netty vs. Tomcat is used under the hood” on stackoverflow.com.

A new approach on protecting your internal IDs with a strong cryptographic schema and many other useful features. Inspired by HashIds.

Global checkstyle config to be reused in different projects. These include my own personal rules so your milage may vary.

IDMask is a Java library for masking internal ids (e.g. from your DB) when they need to be published to hide their actual value and to prevent forging. It has support optional randomisation has a wide support for various Java types including long, UUID and BigInteger.

BCrypt based key derivation function to improve BCrypt as a cryptographic primitive for password hashing and key derivation

Implementation of the single-step key derivation function (KDF) as described in NIST Special Publication 800-56C Rev1 supporting messages digest and HMAC.

Companion code to my article about AES+CBC with Encrypt-then-MAC.

This was originally posted as an answer to the question “Initial bytes incorrect after Java AES/CBC decryption” on stackoverflow.com.

A Java standalone implementation of the bcrypt password hash function. Based on the Blowfish cipher it is the default password hash algorithm for OpenBSD and other systems including some Linux distributions. Includes a CLI Tool.

A convenient pattern to always use interfaces where possible but to keep the code-footprint and complexity of relations small

When starting a new project, all the Proguard configuration goes into that single proguard-rules.pro file. This is fine for the beginning…

What to consider when encrypting your data and how to correctly implement it with AES-GCM.