(Delphi DLL) Get the Server Certificate, Certificate Chain, and Root CA Certificate

Demonstrates how to get the HTTP server certificate, its certificate chain, and the root CA certificate.

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, Http, CertChain, Cert;

...

procedure TForm1.Button1Click(Sender: TObject);
var
http: HCkHttp;
sslCert: HCkCert;
certChain: HCkCertChain;
i: Integer;
numCerts: Integer;
cert: HCkCert;
caCert: HCkCert;

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

http := CkHttp_Create();

// We're getting the SSL/TLS certificate, so make sure to connect to the SSL/TLS port (443).
sslCert := CkHttp_GetServerSslCert(http,'nationalgeographic.com',443);
if (CkHttp_getLastMethodSuccess(http) = False) then
  begin
    Memo1.Lines.Add(CkHttp__lastErrorText(http));
    Exit;
  end;

// Note: Prior to v9.5.0.50, this method would fail if the certificate chain could not 
// be completed to the root.  Starting in v9.5.0.50, the incomplete certificate chain 
// will be returned.  The certificate chain's ReachesRoot property can be examined to 
// see if the chain was completed to the root.
certChain := CkCert_GetCertChain(sslCert);
if (CkCert_getLastMethodSuccess(sslCert) = False) then
  begin
    Memo1.Lines.Add(CkCert__lastErrorText(sslCert));
    CkCert_Dispose(sslCert);
    Exit;
  end;

i := 0;
numCerts := CkCertChain_getNumCerts(certChain);
while i < numCerts do
  begin
    cert := CkCertChain_GetCert(certChain,i);
    Memo1.Lines.Add('SubjectDN ' + IntToStr(i) + ': ' + CkCert__subjectDN(cert));
    Memo1.Lines.Add('IssuerDN ' + IntToStr(i) + ': ' + CkCert__issuerDN(cert));
    CkCert_Dispose(cert);
    i := i + 1;
  end;

// If the certificate chain reaches the root CA cert, then the last cert in the chain
// is the root CA cert.
if (CkCertChain_getReachesRoot(certChain) = True) then
  begin
    caCert := CkCertChain_GetCert(certChain,numCerts - 1);
    Memo1.Lines.Add('CA Root Cert: ' + CkCert__subjectDN(caCert));
    CkCert_Dispose(caCert);
  end;

CkCert_Dispose(sslCert);
CkCertChain_Dispose(certChain);

CkHttp_Dispose(http);

end;