Covid Certificate Checker Library

This Javascript-Library is for parsing and verifying EU Electronic Health Certificates (like the digital EU Covid Certificate) in Web-Applications.

Why another Library

There are already some great Javascript-Libraries, who are helping to decode and verify a digital Covid-Certificate. But most of them targets a NodeJS Environment or make it necessary to use polyfills for NodeJS-Functions. Like the Buffer-Api or the NodeJS-Crypto-Module. The library is intended for web browsers and mobile first.

How does it work?

Have a look at the official repository of the European eHealth network. There is a overview about the Design Principals. And also a rudimentary Implementation-Example.

Usage

You can easily use the Library as ES6 Module.

Install

npm i covid-certificate-checker

Read Certificate

import ElectronicHealthCertificateChecker from "covid-certificate-checker";

//Readout String form QR-Code
const testCertificate = "HC1:....";
const healthCertificateClaim = ElectronicHealthCertificateChecker.decode(testCertificate);
console.log(healthCertificateClaim);

Example:

{
  "iss": "DE",
  "iat": 1643356073,
  "exp": 1622316073,
  "hcert": {
    "v": [
      {
        "ci": "URN:UVCI:01DE/IZ12345A/5CWLU12RNOB9RXSEOP6FG8#W",
        "co": "DE",
        "dn": 1,
        "dt": "2021-05-29",
        "is": "Robert Koch-Institut",
        "ma": "ORG-100031184",
        "mp": "EU/1/20/1507",
        "sd": 2,
        "tg": "840539006",
        "vp": "1119349007"
      }
    ],
    "dob": "1964-08-12",
    "nam": {
      "fn": "Mustermann",
      "gn": "Erika",
      "fnt": "MUSTERMANN",
      "gnt": "ERIKA"
    },
    "ver": "1.0.0"
  }
}

Verify Signature

There are two ways to verify the signature. You can use a Document Signing Certificate like published in the German DSCList (field rawData):

• Test Document Signing Certificate List
• Production Document Signing Certificate List
• Schema Definition

For Verifying it's required that the Browser supports the Web Crypto Api

const {
  healthCertificateClaim,
  isVerified
} = await ElectronicHealthCertificateChecker.verify(testCertificate, rawKey);

Or you can verify the Signature by submitting a TrustList-Object in the format of the German DSCList. The matching is done over the Key Identifier (kid).

const {
  healthCertificateClaim,
  isVerified
} = await ElectronicHealthCertificateChecker.verifyWithTrustList(testCertificate, trustList);

Inspiration

Other projects and libraries I used as inspiration:

• Simple Javascript Implementation of Sign and Verify
• Digital Covid Certificate Library
• DCC-Utils Implementation of the Italien Health Ministry
• COVID Tracker App of Ireland

Build

The build is done with the Typescript-Compiler. Run npm run build.

Testing

You can run the Jasmine-Tests with npm run test:serve or npm run test.

Further Readings

• Hert Spec
• Technical Specifications

Contribute

You can find Testdata under: DGC Testdata

Contribute

The classes I wrote in the src folder are under the MIT license. Not affected by this are for example used schemas, Qr-Codes, files, Documentation or test data that come from other authors. Please feel free to contribute or contact me if you have some Questions.