(CkPython) 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.

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import sys
import chilkat

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

cert = chilkat.CkCert()
success = cert.LoadPfxFile("qa_data/pfx/cert_test123.pfx","test123")
if (success == False):
    print(cert.lastErrorText())
    sys.exit()

fac = chilkat.CkFileAccess()

fileBytes = chilkat.CkByteData()
success = fac.ReadEntireFile("qa_data/pdf/sample.pdf",fileBytes)
if (fac.get_LastMethodSuccess() != True):
    print(fac.lastErrorText())
    sys.exit()

crypt = chilkat.CkCrypt2()

success = crypt.SetSigningCert(cert)

# We can sign any type of file.

sigBytes = chilkat.CkByteData()
success = crypt.OpaqueSignBytes(fileBytes,sigBytes)
if (crypt.get_LastMethodSuccess() != True):
    print(crypt.lastErrorText())
    sys.exit()

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

# We can verify the opaque signature and extract the original data like this
originalData = chilkat.CkByteData()
success = crypt.OpaqueVerifyBytes(sigBytes,originalData)
if (crypt.get_LastMethodSuccess() != True):
    print(crypt.lastErrorText())
    sys.exit()

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

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