pycades script example that verifies attached signature

pycades-verify-signature.py

import pycades

signed_data = pycades.SignedData()

with open('message.txt') as f:
    msg = f.read()
    signed_data.Content = msg

with open('message.txt.sig') as f:
    signature_raw = f.read()

# Success if does not raise an exception
# False positive if root CA cert is not installed (test CA requires a dedicated installation)
signed_data.VerifyCades(signature_raw, pycades.CADESCOM_CADES_X_LONG_TYPE_1)

print('verified')
print('Content', signed_data.Content)

print('Number of signers', signed_data.Signers.Count)
for i in range(signed_data.Signers.Count):
    signer = signed_data.Signers.Item(i + 1) # 1-indexed array
    signer_cert = signer.Certificate
    print('signer', signer_cert.SubjectName)