CkPython

Add a Detached Signature (Separate Key, Header Control)

Demonstrates the Chilkat Mime.AddDetachedSignaturePk2 method, which creates a detached signature with a separately supplied certificate and private key, and a third argument controlling transfer of the existing message header fields to the new outer entity.

Note: The file paths are relative to the application's current working directory. Absolute paths may also be used. Supply the paths appropriate to your own environment.

Background: This combines the two variations — certificate and key supplied separately, plus explicit header placement — for the case that needs both. It is the most flexible of the detached-signature methods; choose it when your key material is separate and you also care about where the message headers end up on the signed result.

Chilkat CkPython Downloads

Download Chilkat for CkPython

CkPython

import sys
import chilkat

success = False

mime = chilkat.CkMime()
success = mime.SetBodyFromPlainText("This message will be signed.")
if (success == False):
    print(mime.lastErrorText())
    sys.exit()

#  Load the certificate and its private key separately.
cert = chilkat.CkCert()
success = cert.LoadFromFile("qa_data/signer.cer")
if (success == False):
    print(cert.lastErrorText())
    sys.exit()

privKey = chilkat.CkPrivateKey()
success = privKey.LoadPemFile("qa_data/signer_privkey.pem")
if (success == False):
    print(privKey.lastErrorText())
    sys.exit()

#  Create a detached signature with separately supplied cert and private key, where the 3rd
#  argument controls whether the existing message header fields are transferred to the new outer
#  multipart/signed entity.
transferHeaderFields = True
success = mime.AddDetachedSignaturePk2(cert,privKey,transferHeaderFields)
if (success == False):
    print(mime.lastErrorText())
    sys.exit()

success = mime.SaveMime("qa_output/signed.eml")
if (success == False):
    print(mime.lastErrorText())
    sys.exit()

print("Detached signature added (headers transferred).")