dcc-utils 0.2.0

Parse DCC

This library takes an image with a QR code or a raw repr. of a vaccine certificate as the parameter and will show the certificate’s content.

from dcc_utils import dcc

dcc_from_img = dcc.from_image("/my/certificate/path")
dcc_from_raw = dcc.from_raw("HC1:6BF...FTPQ3C3F")

Then you can access to payload and kid

assert dcc_from_img.kid == "53FOjX/4aJs="
assert dcc_from_img.payload["v"][0]["ci"] == "URN:UVCI:01:FR:W7V2BE46QSBJ#L"

👉🏻 payload follows EU Digital COVID Certificates JSON Schema Specification

from_image and from_raw methods may rise DCCParsingError

from dcc_utils.exceptions import DCCParsingError

Validate DCC digital signature

signature = b"""
-----BEGIN CERTIFICATE-----
MIIIAjCCBeqgAwIBAgIQAnq8g/T
-----END CERTIFICATE-----
"""
assert my_dcc.check_signature(signature)

check_signature method may rise DCCSignatureError

from dcc_utils.exceptions import DCCSignatureError

Evaluate CertLogic business rules

With dcc-utils you can evaluate business rules against a DCC

from dcc_utils import rule, dcc

my_dcc = dcc.from_image("/my/certificate/path")
my_rule = rule.from_file("/my/rule.json")
print(my_rule.description["en"])
my_rule.evaluate_dcc(my_dcc) # True or False

evaluate_dcc accepts extra variables as a second parameter, e.g. validationClock

import datetime
clock = datetime.datetime(2022, 10, 10, 0, 0, tzinfo=datetime.timezone.utc)
my_rule.evaluate_dcc(
    my_dcc,
    {
        "validationClock": clock,
    },
)

you can also load rules from JSON (from_json), useful to evaluate rules exposed on a server

my_rule = rule.from_json({...})

from_file and from_json method may rise DCCRuleError

from dcc_utils.exceptions import DCCRuleError

Sample data

Digital Green Certificate Gateway (DGCG) samples for all participating countries: https://github.com/eu-digital-green-certificates/dgc-testdata