(Chilkat2-Python) Sign String to create a CAdES-T Signature

This example will sign a string to create a CAdEST-T signature.

Note: This example requires Chilkat v9.5.0.78 or greater.

Chilkat2 Python Downloads install with pip pip3 install chilkat2 or download... Python Module for Windows, Linux, Alpine Linux, MacOS, Solaris

import sys
import chilkat2

# This example requires the Chilkat API to have been previously unlocked.
# See Global Unlock Sample for sample code.

crypt = chilkat2.Crypt2()

# This example will use the certificate + private key currently inserted into a smartcard reader.
cert = chilkat2.Cert()

# If we wish to provide the smartcard PIN (otherwise the user will be prompted by the operating system).
cert.SmartCardPin = "000000"
success = cert.LoadFromSmartcard("")
if (success != True):
    print(cert.LastErrorText)
    sys.exit()

# Note: It is also possible to use certs from .pfx/.p12, .pem, or other sources such as 
# pre-installed Windows certificates.

success = crypt.SetSigningCert(cert)

# Use SHA-256 rather than the default of SHA-1
crypt.HashAlgorithm = "sha256"

# Create JSON that tells Chilkat what signing attributes to include:
attrs = chilkat2.JsonObject()
attrs.UpdateBool("contentType",True)
attrs.UpdateBool("signingTime",True)
attrs.UpdateBool("messageDigest",True)
attrs.UpdateBool("signingCertificateV2",True)

# A CAdES-T signature is one that includes a timestampToken created by an online TSA (time stamping authority).
# We must include the TSA's URL, as well as a few options to indicate what is desired.
# Except for the TSA URL, the options shown here are typically what you would need.
attrs.UpdateBool("timestampToken.enabled",True)
attrs.UpdateString("timestampToken.tsaUrl","https://freetsa.org/tsr")
attrs.UpdateBool("timestampToken.addNonce",False)
attrs.UpdateBool("timestampToken.requestTsaCert",True)
attrs.UpdateString("timestampToken.hashAlg","sha256")

crypt.SigningAttributes = attrs.Emit()

strToSign = "THIS IS MY ID"

bd = chilkat2.BinData()
bd.AppendString(strToSign,"utf-8")

# This creates the CAdES-T signature.  During the signature creation, it
# communicates with the TSA to get a timestampToken.
# The contents of bd are signed and replaced with the CAdES-T signature (which embeds the original content).
success = crypt.OpaqueSignBd(bd)
if (success != True):
    print(crypt.LastErrorText)
    sys.exit()

# Get the signature in base64 format:
print(bd.GetEncoded("base64_mime"))

# Or save the signature to a file.
bd.WriteFile("qa_output/cades-t_sample.p7m")

print("Success.")