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

Signs data contained in a byte array to produce a detached signature (also in a byte array). Also shows how to verify the signature.

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.
# The result is a detached signature (a signature that does not contain the data being signed).

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

success = fac.WriteEntireFile("qa_output/sample.pdf.p7s",sigBytes)
if (fac.LastMethodSuccess != True):
    print(fac.LastErrorText)
    sys.exit()

# We can verify the detached signature like this
verified = crypt.VerifyBytes(fileBytes,sigBytes)
if (crypt.LastMethodSuccess != True):
    print(crypt.LastErrorText)
    sys.exit()

print("Verified = " + str(verified))