Create S/MIME with Opaque Digital Signature

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

Download Chilkat Ruby Library

require 'chilkat'

mime = Chilkat::CkMime.new()

#  Any string argument automatically begins the 30-day trial.
success = mime.UnlockComponent("30-day trial")
if (success != true)
    print "MIME component unlock failed" + "\n"
    exit
end

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

certStore = ccs.OpenCurrentUserStore()

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

if (cert == nil )
    print cert.lastErrorText() + "\n"
    exit
end

#  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:" + "\n";
print mime.getMime() + "\n";

#  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() + "\n"
    exit
end

print "----------------------------------" + "\n";
print "Signed Message:" + "\n";
print mime.getMime() + "\n";

print "Success!" + "\n"

#  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
#  DQYJKoZIhvcNAQEFBQAwVTELMAkGA1UEBhMCWkExJTAjBgNVBAoTHFRoYXd0ZSBDb25zdWx0
#  aW5nIChQdHkpIEx0ZC4xHzAdBgNVBAMTFlRoYXd0ZSBDb2RlIFNpZ25pbmcgQ0EwHhcNMDcw
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#  VGhhd3RlQ29kZVNpZ25pbmdDQS5jcmwwHwYDVR0lBBgwFgYIKwYBBQUHAwMGCisGAQQBgjcC
#  ARYwHQYDVR0EBBYwFDAOMAwGCisGAQQBgjcCARYDAgeAMDIGCCsGAQUFBwEBBCYwJDAiBggr
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# 
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