(Chilkat2-Python) Duplicate OpensSSL to Create Signature using Cert and Key Files

This example duplicates the following:

openssl smime –sign -in something.xml -out something.der -signer mycert.crt -inkey cert.key -outform der –nodetach

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*...

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.

crypt = chilkat2.Crypt2()

# Load the cert and private key from separate files.
cert = chilkat2.Cert()
success = cert.LoadFromFile("myCert.crt")
if (success != True):
    print(cert.LastErrorText)
    sys.exit()

bd = chilkat2.BinData()
success = bd.LoadFile("cert.key")
privkey = chilkat2.PrivateKey()
# Load from any format private key.
# If the file does not need a password, the 2nd arg is ignored.
success = privkey.LoadAnyFormat(bd,"password_if_needed")
if (success != True):
    print(privkey.LastErrorText)
    sys.exit()

success = crypt.SetSigningCert2(cert,privkey)
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.der")
if (success != True):
    print(crypt.LastErrorText)
    sys.exit()

print("Success.")