(Delphi ActiveX) 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 for Delphi Downloads Chilkat ActiveX DLL for Delphi Chilkat non-ActiveX DLL for Delphi * The examples here use the ActiveX DLL.

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Chilkat_TLB;

...

procedure TForm1.Button1Click(Sender: TObject);
var
certUrl: WideString;
http: TChilkatHttp;
bdCert: TChilkatBinData;
success: Integer;
cert: TChilkatCert;
certPath: WideString;
troots: TChilkatTrustedRoots;

begin
// 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

certUrl := 'https://dl.cacerts.digicert.com/DigiCertGlobalRootG3.crt';

http := TChilkatHttp.Create(Self);
bdCert := TChilkatBinData.Create(Self);
success := http.DownloadBd(certUrl,bdCert.ControlInterface);
if (success = 0) then
  begin
    Memo1.Lines.Add(http.LastErrorText);
    Exit;
  end;

// Load it into a Chilkat cert object.
cert := TChilkatCert.Create(Self);
success := cert.LoadFromBd(bdCert.ControlInterface);
if (success = 0) then
  begin
    Memo1.Lines.Add(cert.LastErrorText);
    Exit;
  end;

// Examine the common name,serial, and thumbprint:
Memo1.Lines.Add('CN: ' + cert.SubjectCN);
Memo1.Lines.Add('Serial: ' + cert.SerialNumber);
Memo1.Lines.Add('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.  
certPath := 'qa_data/certs/DigiCertGlobalRootG3.crt';
success := bdCert.WriteFile(certPath);

// To load the cert from a file...
success := cert.LoadFromFile(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:
troots := TChilkatTrustedRoots.Create(Self);

troots.AddCert(cert.ControlInterface);
troots.Activate();

Memo1.Lines.Add(cert.SubjectCN + ' is now trusted for this run of this application.');
end;