(Chilkat2-Python) Sign PDF with Timestamp from TSA (Timestamp Server Authority)

See more PDF Signatures Examples

This example demonstrates how to a sign a PDF that is both long-term validation (LTV) enabled and includes a validating timestamp from a TSA (Timestamp Server Authority).

Note: This example requires Chilkat v9.5.0.85 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.

pdf = chilkat2.Pdf()

# Load a PDF to be signed.
# The "hello.pdf" is available at https://chilkatsoft.com/hello.pdf
success = pdf.LoadFile("qa_data/pdf/hello.pdf")
if (success == False):
    print(pdf.LastErrorText)
    sys.exit()

# Options for signing are specified in JSON.
json = chilkat2.JsonObject()

# In most cases, the signingCertificateV2 and signingTime attributes are required.
json.UpdateInt("signingCertificateV2",1)
json.UpdateInt("signingTime",1)

# Tell Chilkat to create an LTV-enabled (long term validation) signature.
# See PDF Long-Term Validation (LTV) Signature Example for more detailed comments about "ltvOcsp".
json.UpdateBool("ltvOcsp",True)

# Tell Chilkat to request a timestamp from a TSA server and include the timestamp token (1.2.840.113549.1.9.16.2.14)
# in the CMS signature's authentication attributes
json.UpdateBool("timestampToken.enabled",True)

# In this example, we'll use a free TSA server (timestamp.digicert.com), but you may want to use your own timestamp authority server.
json.UpdateString("timestampToken.tsaUrl","http://timestamp.digicert.com")

# If the timestamp server requires a username/password, do the following.  Otherwise omit the following few lines of code.
json.UpdateString("timestampToken.tsaUsername","the_tsa_username")
json.UpdateString("timestampToken.tsaPassword","the_tsa_password")

# When requesting the timestamp token, ask the server to include its certificate in the timestamp token response.
# This allows for the timestamp server's certificate to be included in the LTV validation (i.e. if the timestamp server
# has an OCSP URL, then Chilkat will also do the OCSP request for the timestamp server's certificate.)
json.UpdateBool("timestampToken.requestTsaCert",True)

# Define the appearance of the signature.
json.UpdateInt("page",1)
json.UpdateString("appearance.y","top")
json.UpdateString("appearance.x","left")
json.UpdateString("appearance.fontScale","10.0")
json.UpdateString("appearance.text[0]","Digitally signed by: cert_cn")
json.UpdateString("appearance.text[1]","current_dt")
json.UpdateString("appearance.text[2]","This is an LTV-enabled signature with a TSA timestamp.")

# Load the signing certificate. (Use your own certificate.)
cert = chilkat2.Cert()
success = cert.LoadPfxFile("qa_data/pfx/myPdfSigningCert.pfx","pfxPassword")
if (success == False):
    print(cert.LastErrorText)
    sys.exit()

# Tell the pdf object to use the certificate for signing.
success = pdf.SetSigningCert(cert)
if (success == False):
    print(pdf.LastErrorText)
    sys.exit()

success = pdf.SignPdf(json,"qa_output/hello_ltv_signed_with_timestamp.pdf")
if (success == False):
    print(pdf.LastErrorText)
    sys.exit()

print("The PDF has been successfully cryptographically signed with TSA timestamp and long-term validation.")

# If you open the Signature Panel in Adobe Acrobat, it will indicate that the signature is LTV enabled
# and contains an embedded timestamp: