Swift

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. Swift

func chilkatTest() {
    var success: Bool = false

    let cert = CkoCert()!

    // 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.
    success = cert.load(byCommonName: "My Cert")
    if success == false {
        print("\(cert.lastErrorText!)")
        return
    }

    print("Cert has private key: \(cert.hasPrivateKey())")

    // Load the MIME to be decrypted.
    // We encrypted using this example:  S/MIME Encrypt using Certificate in Apple Keychain
    let mime = CkoMime()!
    success = mime.loadFile(path: "./encrypted.mime")
    if success == false {
        print("\(mime.lastErrorText!)")
        return
    }

    print("\(mime.getMime()!)")
    print("----")

    // 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.decrypt(usingCert: cert)
    if success == false {
        print("\(mime.lastErrorText!)")
        return
    }

    // -------------------------------------
    // 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
    print("\(mime.getMime()!)")

    // Here's the decrypted MIME

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

}