Pascal (Lazarus/Delphi)

Get Certificate CRL Distribution Points

See more Certificates Examples

Demonstrates how to get a certificate's CRL Distribution Points extension data (assuming it exists). In the vast majority of cases, there will be one CRL Distribution Point.

Note: This example requires Chilkat v9.5.0.76 or greater.

Pascal (Lazarus/Delphi)

program ChilkatDemo;

// Demonstrates using the Chilkat Pascal wrapper via the C bridge DLL.
// Builds as a console application under Lazarus (FPC) or Delphi.

{$IFDEF FPC}
  {$MODE DELPHI}
{$ENDIF}
{$APPTYPE CONSOLE}

uses
  {$IFDEF UNIX}
  cthreads,
  {$ENDIF}
  SysUtils,
  CkDllLoader,
  Chilkat.StringBuilder,
  Chilkat.Xml,
  Chilkat.Cert;

// ---------------------------------------------------------------------------

procedure RunDemo;
var
  success: Boolean;
  cert: TCert;
  extensionXmlStr: string;
  xml: TXml;
  sbDistPoint: TStringBuilder;

begin
  success := False;

  cert := TCert.Create;

  success := cert.LoadFromFile('qa_data/certs/test_haswdt.cer');
  if (success <> True) then
    begin
      WriteLn(cert.LastErrorText);
      Exit;
    end;

  //  Get the CRL Distribution Points extension, which is at OID 2.5.29.31
  extensionXmlStr := cert.GetExtensionAsXml('2.5.29.31');
  if (cert.LastMethodSuccess = False) then
    begin
      WriteLn('Certificate does not have the CDP extension.');
      Exit;
    end;

  xml := TXml.Create;
  xml.LoadXml(extensionXmlStr);

  //  See what we have..
  WriteLn(xml.GetXml());

  //  We should get XML like this:

  //  <?xml version="1.0" encoding="utf-8" ?>
  //  <sequence>
  //      <sequence>
  //          <contextSpecific tag="0" constructed="1">
  //              <contextSpecific tag="0" constructed="1">
  //                  <contextSpecific tag="6" constructed="0">aHR0cDovL2NybC5jb21vZG9jYS5jb20vQ09NT0RPUlNBQ2xpZW50QXV0aGVudGljYXRpb25hbmRTZWN1
  //  cmVFbWFpbENBLmNybA==</contextSpecific>
  //              </contextSpecific>
  //          </contextSpecific>
  //      </sequence>
  //  </sequence>
  //  

  //  Assuming there is one CRL Distribution Point...
  sbDistPoint := TStringBuilder.Create;
  success := xml.GetChildContentSb('sequence|contextSpecific|contextSpecific|contextSpecific',sbDistPoint);
  if (success = True) then
    begin
      sbDistPoint.Decode('base64','utf-8');
      WriteLn('CRL Distribution Point:  ' + sbDistPoint.GetAsString());
    end;

  //  Sample output:
  //  CRL Distribution Point:  http://crl.comodoca.com/COMODORSAClientAuthenticationandSecureEmailCA.crl


  cert.Free;
  xml.Free;
  sbDistPoint.Free;

end;

// ---------------------------------------------------------------------------

begin

  try
    RunDemo;
  except
    on E: Exception do
      WriteLn('Unhandled exception: ', E.ClassName, ': ', E.Message);
  end;

  WriteLn;
  {$IFDEF MSWINDOWS}
  WriteLn('Press Enter to exit...');
  ReadLn;
  {$ENDIF}
end.