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

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

...

procedure TForm1.Button1Click(Sender: TObject);
var
http: HCkHttp;
success: Boolean;
cert: HCkCert;
success: Boolean;

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

http := CkHttp_Create();

// On Windows, a pre-installed certificate can be loaded in a number of different ways.
// This example loads by the common name:
cert := CkCert_Create();
success := CkCert_LoadByCommonName(cert,'My ECA Medium Assurance Identity Certificate');
if (success <> True) then
  begin
    Memo1.Lines.Add(CkCert__lastErrorText(cert));
    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 (CkCert_HasPrivateKey(cert) <> True) 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 := CkHttp_SetSslClientCert(http,cert);
if (success <> True) then
  begin
    Memo1.Lines.Add(CkHttp__lastErrorText(http));
    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.

CkHttp_Dispose(http);
CkCert_Dispose(cert);

end;