Create S/MIME with Opaque Digital Signature

Python example to create a simple S/MIME message with an attached (opaque) digital signature.

Download Chilkat Python Library

import sys
import chilkat

mime = chilkat.CkMime()

#  Any string argument automatically begins the 30-day trial.
success = mime.UnlockComponent("30-day trial")
if (success != True):
    print "MIME component unlock failed"
    sys.exit()

#  Find our digital certificate from the Current User certificate store.
ccs = chilkat.CkCreateCS()

certStore = ccs.OpenCurrentUserStore()

cert = certStore.FindCertBySubjectCN("Chilkat Software, Inc.")

if (cert == None ):
    print cert.lastErrorText()
    sys.exit()

#  Our MIME object is currently empty.  Add some header fields
#  and a body:
mime.AddHeaderField("subject","this is a test")
mime.AddHeaderField("test123","this is a test 123")
mime.put_ContentType("text/plain")
mime.put_Charset("iso-8859-1")
mime.SetBodyFromPlainText("This is the body")

print "Original MIME message:"
print mime.getMime()

#  The original MIME looks like this:
#  ----------------------------------
#  subject: this is a test
#  test123: this is a test 123
#  content-type: text/plain;
#  	 charset="iso-8859-1"
# 
#  This is the body
#  ----------------------------------

#  Convert the MIME to a signed message.  The original MIME
#  is embedded in
success = mime.ConvertToSigned(cert)
if (success != True):
    print mime.lastErrorText()
    sys.exit()

print "----------------------------------"
print "Signed Message:"
print mime.getMime()

print "Success!"

#  The resulting S/MIME looks like this:
#  --------------------------------
#  subject: this is a test
#  test123: this is a test 123
#  content-disposition: attachment;
#  	 filename="smime.p7m"
#  content-transfer-encoding: base64
#  content-type: application/x-pkcs7-mime;
#  	name="smime.p7m";smime-type=signed-data
# 
#  MIIGgAYJKoZIhvcNAQcCoIIGcTCCBm0CAQExCzAJBgUrDgMCGgUAMIGKBgkqhkiG9w0BBwGg
#  fQR7c3ViamVjdDogdGhpcyBpcyBhIHRlc3QNCnRlc3QxMjM6IHRoaXMgaXMgYSB0ZXN0IDEy
#  Mw0KY29udGVudC10eXBlOiB0ZXh0L3BsYWluOw0KCSBjaGFyc2V0PSJpc28tODg1OS0xIg0K
#  DQpUaGlzIGlzIHRoZSBib2R5oIID2TCCA9UwggM+oAMCAQICEHii5NwCYuzOsaLXvSTV15Iw
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# 
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