Create PKCS7 Signature using .cer and .key Files

Uses a digital certificate (.cer file) and private key file to create a PKCS7 signature.

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import sys
import chilkat

#  First, load the .cer and .key files into Chilkat objects...
cert = chilkat.CkCert()

success = cert.LoadFromFile("myCert.cer")
if (success != True):
    print cert.lastErrorText()
    sys.exit()

privKey = chilkat.CkPrivateKey()
password = "myPassword"
#  The private key object provides different methods for
#  loading keys of many different formats.
#  This example loads a PKCS8 encrypted private key.
success = privKey.LoadPkcs8EncryptedFile("myPrivateKey.key",password)
if (success != True):
    print privKey.lastErrorText()
    sys.exit()

#  NOTE:  In this example, the .cer should contain the public key
#  that corresponds to the private key.

crypt = chilkat.CkCrypt2()

#  Any string argument automatically begins the 30-day trial.
success = crypt.UnlockComponent("30-day trial")
if (success != True):
    print crypt.lastErrorText()
    sys.exit()

#  Set the certifcate + private key to be used for signing:
crypt.SetSigningCert2(cert,privKey)

pkcs7 = chilkat.CkByteData()

textToSign = "This is the text to be signed."
success = crypt.SignString(textToSign,pkcs7)
if (success == False):
    print crypt.lastErrorText()
    sys.exit()

#  Save the PKCS7 signature to a file.
success = pkcs7.saveFile("out_pkcs7.p7s")
if (success == False):
    print "Failed to save output file."
else:
    print "Success."