@airgap/ur-registry-xtz

ur-registry-xtz

This repository defines UR Types based on TZIP-25

The project is still in an early stage, there may still be breaking changes.

Introduction

This library allows internet connected wallets to connect to offline signers via QR codes. One shortcoming of QR codes is that the data they can contain is limited. The BC UR standard solves this by using fountain codes.

Apps that want to adopt this standard need to be able to show "animated" QR codes, as well as be able to scan multiple QR codes in sequence in order to send or receive larger payloads.

Examples

Take a look at example.ts. You can run it with npm run example

Reading Public Key

const qrData =
  "ur:xtz-public-key/oxaohdcxcfbagrbatdjtwpgmadecswuerezchkfxgaldwdlyctcetksraoahrnoslyjloxwdaxadaafyjladzmspahjlfpinjpflhsjocxdpcxfwjlkpjtiaihnemttbmt";

const decoder = new URRegistryDecoder();

// "Receive" qr data that has been scanned
decoder.receivePart(qrData);

// Check if the data is complete
if (decoder.isComplete() && decoder.isSuccess()) {
  const publicKey = TezosPublicKey.fromCBOR(decoder.resultUR().cbor);

  publicKey.getKeyType();
  publicKey.getPublicKey();
  // ...
} else {
  // Decoding is not complete yet, scan next part and call `decoder.receivePart(qrData);` again.
}

Sharing Public Key

const pubKey = new TezosPublicKey({
  publicKey: Buffer.from(
    "190e4b0ed26eec520135c6deb5fd59434989ea811f1ccfc30205bea7816fa4ea",
    "hex"
  ),
  keyType: PublicKeyType.ED25519,
  masterFingerprint: Buffer.from("6f01ffc8", "hex"),
  label: "Test",
});

// Set size to something where QR codes are easily readable by scanners. This value is very low to simulate larger payloads.
const qrSize = 10;

const encoded = pubKey.toUREncoder(qrSize);

for (let x = 0; x < encoded.fragmentsLength * 2; x++) {
  console.log(encoded.nextPart().toUpperCase());
  // Show all those strings as QR codes
  // Use ".toUpperCase()" for better QR code encoding
  // Do not "repeat" the QR codes, just keep calling "nextPart". The parts after 5/5 are technically not needed, but it contains parts of the previous QR codes and allows transmission to succeed, even if some QRs are lost.
}

Installing

This package is currently not released on NPM because it's still in beta.

To test it, simply copy the files from the /src folder into your own project.