Building a Bluetooth DAC with Raspberry Pi Zero W

My car comes with a built-in Bluetooth hands-free but unfortunately it does not support audio streaming. Luckily there is an AUX input available which uses a regular 3,5 mm jack. Perfect opportunity for a DIY project. I built the Bluetooth DAC using Raspberry Pi Zero W and a DAC hat. This post depicts the details of this project. Continue reading “Building a Bluetooth DAC with Raspberry Pi Zero W”

How to sign and verify using OpenSSL

Being able to verify that a piece of data originates from a trusted source (authenticity) and that it has not been altered in transit (integrity) is a common requirement in many use cases. It is needed for instance when distributing software packages and installers and when delivering firmware to an embedded device. Digital signatures allow the recipient to verify both authenticity and integrity of the received document. This blog post describes how to use digital signatures with OpenSSL in practice. First part describes what is a digital signature and then the second part shows how to use OpenSSL sign and verify functions to work with signatures.
Continue reading “How to sign and verify using OpenSSL”