[SOLVED] How to validate Aadhaar XML signature in Python?

How to validate Aadhaar XML signature in Python?

I'm trying to do XML signature validation. Here is the link to Aadhaar Paperless Offline e-kyc tutorial https://uidai.gov.in/ecosystem/authentication-devices-documents/about-aadhaar-paperless-offline-e-kyc.html

with open('/home/user/Downloads/uidai_auth_sign_prod_2023.cer', 'rb') as f:
     key = f.read()
import xml.etree.ElementTree as ET
tree=ET.parse("/home/user/Downloads/offlineaadhaar202205040207.xml")
root = tree.getroot()
print(root)
try:
    verified_data = XMLVerifier().verify(root, require_x509=False, x509_cert=key).signed_xml
    print("Data is : %s" % verified_data)
except Exception as exce:
    print(exce)

This code is giving error:

Signature verification failed: invalid padding

If there is any other solution to verify xml signature. please let us know.

Solution

I have found out XMLVerifier usefull to verify signed xml. pip package need to be install

pip install signxml

here is my working snippet

Code

from signxml import XMLVerifier
aadhar_file = '<path_to_signed_aadhaar_xml>'
cert = open('path_to_uidai_auth_sign_prod_2023.pem', "r+").read()
root = le.parse(aadhar_file).getroot()
try:
    verify = XMLVerifier().verify(root, x509_cert=cert)
except Exception as e:
    print(str(e))

In case of invalid signature this will throw an exception

InvalidDigest: Digest mismatch for reference 0

NOTE: Kindly use valid certificate(Based on recommended by https://uidai.gov.in/ecosystem/authentication-devices-documents/about-aadhaar-paperless-offline-e-kyc.html) to validate aadhaar xml