Chilkat2-Python

Sign String to create a CAdES-T Signature

See more CAdES Examples

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

import sys
import chilkat2

success = False

# 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.")