(Xojo Plugin) S/MIME Decrypt using Certificate and Private Key in Apple Keychain

See more Apple Keychain Examples

Decrypts S/MIME using a certificate with private key found in the Apple Keychain.

Chilkat Xojo Plugin Download Xojo Plugin for Windows, Linux, Mac OS X, and ARM, ARM64

Dim cert As New Chilkat.Cert

// Load the certificate to be used for decryption by the Subject Common Name
// On MacOS and iOS, Chilkat will search the Keychain(s) for the matching certificate.
// Note: The private key must be present to decrypt.
Dim success As Boolean
success = cert.LoadByCommonName("My Cert")
If (success = False) Then
    System.DebugLog(cert.LastErrorText)
    Return
End If

System.DebugLog("Cert has private key: " + Str(cert.HasPrivateKey()))

// Load the MIME to be decrypted.
// We encrypted using this example:  S/MIME Encrypt using Certificate in Apple Keychain
Dim mime As New Chilkat.Mime
success = mime.LoadMimeFile("./encrypted.mime")
If (success = False) Then
    System.DebugLog(mime.LastErrorText)
    Return
End If

System.DebugLog(mime.GetMime())
System.DebugLog("----")

// Here's the encrypted MIME:

// Subject: test
// SomeHeader: 123
// Content-Type: application/x-pkcs7-mime; name="smime.p7m"; smime-type="enveloped-data"
// Content-Disposition: attachment; filename="smime.p7m"
// Content-Transfer-Encoding: base64
// 
// MIICSwYJKoZIhvcNAQcDoIICPDCCAjgCAQAxggGzMIIBrwIBADCBljCBgTELMAkGA1UEBhMCSVQx
// EDAOBgNVBAgMB0JlcmdhbW8xGTAXBgNVBAcMEFBvbnRlIFNhbiBQaWV0cm8xFzAVBgNVBAoMDkFj
// dGFsaXMgUy5wLkEuMSwwKgYDVQQDDCNBY3RhbGlzIENsaWVudCBBdXRoZW50aWNhdGlvbiBDQSBH
// MwIQPCWvkSv8oQ7xRmEHJ6TzEDANBgkqhkiG9w0BAQEFAASCAQB3VZvHRE5EWxug7Sckpcz1ucDZ
// YiTKiqmyPt75MhzNRQLtKFx/jWwlemUwnPMzeu6yutCkZ74Bdn7MBsfDqV3bUz43wAu+fRBteGvF
// mTc00MfY8L7o8dkpj4AqAOCj4hKQzbSE99GvSzyXcPE2Gm5NrOPtKxqfFqbBRTCb4fBZP84LaL+x
// rnYfrM4qXTppixyN8iFYCd4maEbMu/GA5o+j0BkDDnx42pILDoAGV/ERyx55Y3Nc2Mhm/cITBMNn
// g7uS9KPrlYizNaqVu09Hi9jg4gdZaRiTjUqg05tSOk/YqIQxTgfscwSPY92/ewpI6e1EHtLt8Q33
// gWCbERptSntUMHwGCSqGSIb3DQEHATAdBglghkgBZQMEAQIEENm1AxeXlEMx7p6McjHIj5CAUEQj
// 0GuJ5LnTqiqIjOiwmwNidl1N1TRluxX5vAQvwBuYE6bQK4+i04yn2Av3cucW4kvxgP2Nmni+XgQt
// aPPKlasaVceEeZ15IYjw77/m3YYn

// -------------------------------------
// Decrypt the MIME.
success = mime.DecryptUsingCert(cert)
If (success = False) Then
    System.DebugLog(mime.LastErrorText)
    Return
End If

// -------------------------------------
// Note: A password dialog may be shown, possibly twice, when accessing the private key.
// See the following blog post explaining how to suppress the dialog:
// Suppress Password Dialog when Accessing Private Key in Apple Keychain

// Show the unencrypted MIME
System.DebugLog(mime.GetMime())

// Here's the decrypted MIME

// Subject: test
// SomeHeader: 123
// Content-Type: text/plain
// 
// This is the body.