(Delphi ActiveX) Use Installed Cert on Windows for TLS Client Authentication

Demonstrates how to use a certificate that has already been installed on a Windows PC for TLS client authentication.

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
http: TChilkatHttp;
success: Integer;
cert: TChilkatCert;
success: Integer;

begin
// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

http := TChilkatHttp.Create(Self);

// On Windows, a pre-installed certificate can be loaded in a number of different ways.
// This example loads by the common name:
cert := TChilkatCert.Create(Self);
success := cert.LoadByCommonName('My ECA Medium Assurance Identity Certificate');
if (success <> 1) then
  begin
    Memo1.Lines.Add(cert.LastErrorText);
    Exit;
  end;

// Make sure this certificate has a private key available.  
// It should be a private key such that when the certificate was installed, it was marked as "exportable"
// so that authorized programs are able to access the private key.
if (cert.HasPrivateKey() <> 1) then
  begin
    Memo1.Lines.Add('A private key is needed for TLS client authentication.');
    Memo1.Lines.Add('This certificate has no private key.');
    Exit;
  end;

// Set the certificate to be used for mutual TLS authentication
// (i.e. sets the client-side certificate for two-way TLS authentication)
success := http.SetSslClientCert(cert.ControlInterface);
if (success <> 1) then
  begin
    Memo1.Lines.Add(http.LastErrorText);
    Exit;
  end;

// At this point, the HTTP object instance is setup with the client-side cert, and any SSL/TLS
// connection will automatically use it if the server demands a client-side cert.
end;