Delphi ActiveX

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.

Delphi ActiveX

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
success: Integer;
bdCrl: TChilkatBinData;
asn: TChilkatAsn;
xml: TChilkatXml;
i: Integer;
count_i: Integer;
tagPath: WideString;
j: Integer;
count_j: Integer;
k: Integer;
count_k: Integer;
revokedCertSerialHex: WideString;
dateRevoked: WideString;
dt: TCkDateTime;

begin
success := 0;

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

// Load a binary .crl file.
bdCrl := TChilkatBinData.Create(Self);
success := bdCrl.LoadFile('qa_data/crl/ca1.crl');
if (success <> 1) then
  begin
    Memo1.Lines.Add('Failed to load CRL file.');
    Exit;
  end;

asn := TChilkatAsn.Create(Self);
success := asn.LoadBd(bdCrl.ControlInterface);
if (success <> 1) then
  begin
    Memo1.Lines.Add(asn.LastErrorText);
    Exit;
  end;

// Convert ASN.1 to XML and load into xml and re-emit for pretty printing..
xml := TChilkatXml.Create(Self);
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(Self);

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');
            Memo1.Lines.Add('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);
            Memo1.Lines.Add('date revoked: ' + dt.GetAsRfc822(0));

            k := k + 1;
          end;

        j := j + 1;
      end;

    i := i + 1;
  end;
end;