Creating a .jar executable in an Android Studio project
This article describes how to add a CLI module to an existing Android Studio project that generates an executable .jar archive. The primary audience are software engineers working on Android.
When developing for Android – or other mobile platforms – the change-to-effect latency can be often quite high due to the involved compilation and cross-device communication. The regular unit tests get around this by executing in a VM on the host machine....
Android support for Elliptic Curves (EC) in KeyPairGenerator
This article discusses the support for elliptic curves on Android. Its primary audience are engineers implementing or maintaining cryptographic protocols on Android. It hopefully also shows up as a helpful result when searching for error messages.
During a recent cryptography project on Android, I found that only few Elliptic Curves are supported by the built-in key pair generator. The typical error messages I got were along the line of java.security.InvalidAlgorithmParameterException: unknown curve name....
Password hashing on Android
This article explains why password hashing is important and how to do it properly on Android. The primary audience are software engineers working with passwords.
Password hashing or password-based key derivation takes a password from the user as input and generates key material as output. This is a helpful thing because many people struggle to memorize 256-bit encryption keys. The standard procedure is to pass the user password through the password hashing function, and then use the derived key for cryptographic operations....