Pascal (Lazarus/Delphi)

Load .crl, Convert to XML, Get Revoked Serial Numbers and Dates

See more Certificates Examples

Load a binary .crl file (Certificate Revocation List), converts to XML, and then gets the revoked certificate serial numbers and revocation dates.

Note: This example requires Chilkat v9.5.0.77 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.Xml,
  Chilkat.Asn,
  Chilkat.BinData,
  Chilkat.CkDateTime;

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

procedure RunDemo;
var
  success: Boolean;
  bdCrl: TBinData;
  asn: TAsn;
  xml: TXml;
  i: Integer;
  count_i: Integer;
  tagPath: string;
  j: Integer;
  count_j: Integer;
  k: Integer;
  count_k: Integer;
  revokedCertSerialHex: string;
  dateRevoked: string;
  dt: TCkDateTime;

begin
  success := False;

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

  //  Load a binary .crl file.
  bdCrl := TBinData.Create;
  success := bdCrl.LoadFile('qa_data/crl/ca1.crl');
  if (success <> True) then
    begin
      WriteLn('Failed to load CRL file.');
      Exit;
    end;

  asn := TAsn.Create;
  success := asn.LoadBd(bdCrl);
  if (success <> True) then
    begin
      WriteLn(asn.LastErrorText);
      Exit;
    end;

  //  Convert ASN.1 to XML and load into xml and re-emit for pretty printing..
  xml := TXml.Create;
  xml.LoadXml(asn.AsnToXml());
  success := xml.SaveXml('qa_output/crl.xml');

  //  Use this online tool to generate parsing code from CRL XML: 
  //  Generate Parsing Code from XML

  //  Here's code to parse the XML.  This code was generated by the above tool,
  //  and then we modified it by removing unneeded code and changing some names

  dt := TCkDateTime.Create;

  i := 0;
  count_i := xml.NumChildrenHavingTag('sequence');
  while i < count_i do
    begin
      xml.I := i;

      j := 0;
      count_j := xml.NumChildrenHavingTag('sequence[i]|sequence');
      while j < count_j do
        begin
          xml.J := j;

          k := 0;
          count_k := xml.NumChildrenHavingTag('sequence[i]|sequence[j]|sequence');
          while k < count_k do
            begin
              xml.K := k;

              //  Get the revoked certificate's serial number in uppercase hex.
              revokedCertSerialHex := xml.GetChildContent('sequence[i]|sequence[j]|sequence[k]|int');
              WriteLn('serial number: ' + revokedCertSerialHex);

              //  Get the date/time revoked.  It will be a string formatted as "YYMMDDhhmmssZ", such as "181023093028Z"
              dateRevoked := xml.GetChildContent('sequence[i]|sequence[j]|sequence[k]|utctime');

              //  Starting in Chilkat v9.5.0.77, date/time strings formatted as YYMMDDhhmmssZ can be parsed as follows:
              dt.SetFromTimestamp(dateRevoked);
              WriteLn('date revoked: ' + dt.GetAsRfc822(False));

              k := k + 1;
            end;

          j := j + 1;
        end;

      i := i + 1;
    end;



  bdCrl.Free;
  asn.Free;
  xml.Free;
  dt.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.