Advanced Signature Example

The following Python example shows how to attach an advanced signature (Amtssignatur for example) to a PDF file.

1. Fetch an access token from Keycloak
2. Upload the PDF
3. Extract the signed PDF from the response

import os
from urllib.request import urlopen

import requests
from pyld import jsonld

KEYCLOAK_URL = "https://auth-demo.tugraz.at/auth"
API_URL = "https://api-demo.tugraz.at"
PDF_IN_PATH = 'example.pdf'

# Credentials
CLIENT_ID="<keycloak-client-id>"
CLIENT_SECRET="<keycloak-client-secret>"

# Fetch a token pair
TOKEN_URL = KEYCLOAK_URL + "/realms/tugraz-vpu/protocol/openid-connect/token"
r = requests.post(
    TOKEN_URL, auth=(CLIENT_ID, CLIENT_SECRET),
    data={'grant_type': 'client_credentials'})
r.raise_for_status()
access_token = r.json()["access_token"]

# Make a signing request
with open(PDF_IN_PATH, 'rb') as h:
    r = requests.post(
        API_URL + "/esign/advancedly-signed-documents",
        headers={'Authorization': 'Bearer ' + access_token},
        params={"profile": "sap"},
        files={'file': (PDF_IN_PATH, h)})
    r.raise_for_status()

# Normalize the response
context = {
    'contentSize': 'https://schema.org/contentSize',
    'contentUrl': 'http://schema.org/contentUrl',
    'name': 'http://schema.org/name',
}
response = jsonld.compact(r.json(), context)

# Write the signed data to a file
with urlopen(response["contentUrl"]) as h:
    out_path = os.path.basename(response["name"])
    with open(out_path, 'wb') as wh:
        wh.write(h.read())