rsp6-decoder

This is a set of tools to decode UK National Rail electronic ticket barcodes, specifically RSP6 format, as explained in the blog post "Reversing UK mobile rail tickets".

If you're interested in a working demo, check out the hosted version at eta.st/tickets/.

What's in this repo?

• This repo is primarily a Rust crate that can decode these tickets, given a scanned barcode string (starting with 06...). Look at the decode_ticket function for the main entry point.
• A website that embeds the crate for demo purposes (powering the hosted version) is inside rsp6-webshite/.
  • This will require compiling the main crate for WASM using wasm-pack build --features wasm.
  • If you get errors decoding at runtime, you might need to replace references to wbindgen_realloc in pkg/rsp6_decoder_bg.js with undefined. It's unclear why this happens.
• spec.pdf has a janky table showing what all the fields in a decoded ticket look like.
  • spec.ods is the janky spreadsheet that was used to make this.
• keys.json has a copy of all the ticket public keys, as of 2023-01.
  • decode.py was a hacky Python script to make these from some binary plist I found at some point. You can ignore it.

License

This is all MIT. Please go forth and use it to make your own ticket stuff!