(CkPython) Duplicate OpensSSL to Sign File and Output Binary DER

This example duplicates the following:

openssl smime -sign -in INPUT.xml -signer SIGN.PEM -passin pass:MYPASS -outform der -binary -nodetach -out SIGNED.P7M

Note: Although "smime" is the OpenSSL command, it's not actually producing S/MIME. The arguments "-outform der -binary" indicates that the output is binary DER (i.e. the PKCS7 binary signature). The input can be any type of file: XML, PDF, JPG, ... *anything*...

Chilkat Python Downloads install with pip pip3 install chilkat or download... Python Module for Windows, MacOS, Linux, Alpine Linux, Solaris

import sys
import chilkat

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

crypt = chilkat.CkCrypt2()

# Load the PEM containing cert + private key.
pem = chilkat.CkPem()
success = pem.LoadPemFile("qa_data/pem/myPem.pem","password")
if (success != True):
    print(pem.lastErrorText())
    sys.exit()

# privkey is a CkPrivateKey
privkey = pem.GetPrivateKey(0)
if (pem.get_LastMethodSuccess() != True):
    print(pem.lastErrorText())
    sys.exit()

# cert is a CkCert
cert = pem.GetCert(0)
if (pem.get_LastMethodSuccess() != True):

    print(pem.lastErrorText())
    sys.exit()

success = crypt.SetSigningCert2(cert,privkey)
if (success != True):

    print(crypt.lastErrorText())
    sys.exit()

# Alternatively, we could use a .pfx/.p12 file.
# (Chilkat also supports other formats/sources for cert/private keys...)
certFromP12 = chilkat.CkCert()
success = certFromP12.LoadPfxFile("qa_data/p12/myP12.p12","password")
if (success != True):
    print(certFromP12.lastErrorText())
    sys.exit()

# The certificate, when loaded from a .pfx/.p12, will automatically 
# include the associated private key, assuming it's present in the .p12.
# We don't have to explicitly provide the private key as in the
# lines of code above that use the PEM file.
success = crypt.SetSigningCert(certFromP12)
if (success != True):
    print(crypt.lastErrorText())
    sys.exit()

# Create the opaque signature (PKCS7 binary DER that contains both the signature and original file data).
success = crypt.CreateP7M("qa_data/infile.anything","qa_output/outfile.p7m")
if (success != True):
    print(crypt.lastErrorText())
    sys.exit()

print("Success.")