Add features to manually decode raw data from QR codes

[brozkeff]

Feature description

This command line-tool should be able to parse data obtained directly from any QR code with certificate (starting with HC1:...) either in one step or manually any step at a time to be able to easily reverse engineer the payload of the JSON, the signature etc. without the need to fetch independent base45 python/rust libraries etc. Basically the workflow the validation apps that decode the QR code and parse and interpret it should be accessible for anyone via commandline.

Problem and motivation

IETF draft for base45 has been published only recently (1 July 2021) and apart from Python and Rust libraries and the reference implementation in this github repository no tool to directly base45 decode/encode on the command line or via some online tool exists. Performing the other steps such as decoding and verifying the serialized binary data, uncompressing via zlib could be streamlined as a easy to use command-line toolbox. Even technically savvy people tend to misunderstand how the certificates are cryptographically signed and appear to believe that they can simply be forged.

Is this something you're interested in working on

No, I don't have the programming skills to do so, I just tried (without success) to obtain a linux tool to base45 decode string without success and was surprised such a simple thing (for base64 e.g.) is so difficult right now for base45 as it is so new.