greenpass

This repository contains a library and a command line utility in Go for parsing QR codes containing EU Digital COVID certificates.

Command line

Run the greenpass utility under cmd/greenpass. It currently supports PNG and JPEG.

Usage:

$ ./greenpass
Usage: ./greenpass <file name>

Example:

Download an example QR code, like https://github.com/ehn-dcc-development/dcc-testdata/blob/main/IE/png/1_qr.png .

Then run

$ go run . 1_qr.png
Name             : Jane Bloggs
Date of Birth    : 1988-06-07
Status           : partially vaccinated (1 of 2 doses)
Vaccination date : 2021-05-06

Library

You can use Read or Decode.

• Read(r io.Reader) receives a reader, like a file handle, and returns the COVID certificate object. It calls Decode under the hood.
• Decode receives an image.Image and returns the COVID certificate object.

Examples:

Read:

fd, _ := os.Open("myqrcode.png")
gp, _ := greenpass.Read(fd)
fmt.Printf("%+v", gp)

Decode:

img, _, _ := image.Decode(reader)
gp, _ := greenpass.Decode(img)
fmt.Printf("%+v", gp)

Generated code

Some data structures are generated via tools/generate_types. If you need to regenerate them (e.g. because they were updated), just run go generate in the top level directory.

Useful links

• Technical Specifications for EU Digital COVID Certificates
• Electronic Health Certificate specification
• Digital COVID Certificate JSON schema
• Digital COVID Certificate test data
• Online Digital COVID Certificate decoder with a technical explanation
• Reverse engineering digital COVID-19 certificates