(Chilkat2-Python) Sign a Byte Array to Create an Opaque Signature in a Byte Array

Signs data contained in a byte array to produce an opaque signature (also in a byte array). An opaque signature is a PKCS7 signature (also known as CAdES) that embeds the signed data. Also shows how to verify the signature and extract the original data.

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.

cert = chilkat2.Cert()
success = cert.LoadPfxFile("qa_data/pfx/cert_test123.pfx","test123")
if (success == False):
    print(cert.LastErrorText)
    sys.exit()

fac = chilkat2.FileAccess()

# fileBytes is a memoryview
fileBytes = fac.ReadEntireFile("qa_data/pdf/sample.pdf")
if (fac.LastMethodSuccess != True):
    print(fac.LastErrorText)
    sys.exit()

crypt = chilkat2.Crypt2()

success = crypt.SetSigningCert(cert)

# We can sign any type of file.

# sigBytes is a memoryview
sigBytes = crypt.OpaqueSignBytes(fileBytes)
if (crypt.LastMethodSuccess != True):
    print(crypt.LastErrorText)
    sys.exit()

success = fac.WriteEntireFile("qa_output/sample.pdf.p7m",sigBytes)
if (fac.LastMethodSuccess != True):
    print(fac.LastErrorText)
    sys.exit()

# We can verify the opaque signature and extract the original data like this

# originalData is a memoryview
originalData = crypt.OpaqueVerifyBytes(sigBytes)
if (crypt.LastMethodSuccess != True):
    print(crypt.LastErrorText)
    sys.exit()

success = fac.WriteEntireFile("qa_output/sample.pdf",originalData)
if (fac.LastMethodSuccess != True):
    print(fac.LastErrorText)
    sys.exit()

print("Signature is verified and the original data was extracted.")