(Swift 3,4,5...) Download and Trust the DigiCert Global Root CA

Demonstrates how to download a root certificate and trust it.

For more information, see https://www.digicert.com/digicert-root-certificates.htm

Chilkat Downloads for the Swift Programming Language MAC OS X (Cocoa) Objective-C/Swift Libs iOS Objective-C/Swift Libs

func chilkatTest() {
    // This requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    // In this example, the URLs for the DigiCert root CA certs are available at this web page:
    // https://www.digicert.com/digicert-root-certificates.htm

    // This example downloads the "DigiCert Global Root G3"
    // Valid until: 15/Jan/2038
    // Serial #: 05:55:56:BC:F2:5E:A4:35:35:C3:A4:0F:D5:AB:45:72
    // Thumbprint: 7E04DE896A3E666D00E687D33FFAD93BE83D349E

    var certUrl: String? = "https://dl.cacerts.digicert.com/DigiCertGlobalRootG3.crt"

    let http = CkoHttp()!
    let bdCert = CkoBinData()!
    var success: Bool = http.downloadBd(certUrl, binData: bdCert)
    if success == false {
        print("\(http.lastErrorText!)")
        return
    }

    // Load it into a Chilkat cert object.
    let cert = CkoCert()!
    success = cert.load(fromBd: bdCert)
    if success == false {
        print("\(cert.lastErrorText!)")
        return
    }

    // Examine the common name,serial, and thumbprint:
    print("CN: \(cert.subjectCN!)")
    print("Serial: \(cert.serialNumber!)")
    print("Thumbprint: \(cert.sha1Thumbprint!)")

    // Output from the above:
    // CN: DigiCert Global Root G3
    // Serial: 055556BCF25EA43535C3A40FD5AB4572
    // Thumbprint: 7E04DE896A3E666D00E687D33FFAD93BE83D349E

    // If desired, the certificate can be saved to a local file so it does not need
    // to be downloaded from the website every time.  
    var certPath: String? = "qa_data/certs/DigiCertGlobalRootG3.crt"
    success = bdCert.writeFile(certPath)

    // To load the cert from a file...
    success = cert.load(fromFile: certPath)

    // Do the following to add the cert to the collection of trusted roots
    // for this application.  (Note:  The trust is not persisted.  Each time the
    // application runs, it should load the cert (from whatever source, whether it is
    // a file, a database,etc.) and do the following:
    let troots = CkoTrustedRoots()!

    troots.add(cert)
    troots.activate()

    print("\(cert.subjectCN!) is now trusted for this run of this application.")

}