Lazarus Pascal

Convert ASN.1 to/from Binary DER, XML, and Base64

Demonstrates how to convert ASN.1 from and to any of the following formats: binary DER, Base64, and XML. Lazarus Pascal

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;

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

procedure RunDemo;
var
  success: Boolean;
  asn: TAsn;
  strXml: string;
  xml: TXml;
  strBase64: string;
  asn2: TAsn;
  asn3: TAsn;

begin
  success := False;

  asn := TAsn.Create;

  //  Begin with loading ASN.1 from a binary DER/BER format file.
  success := asn.LoadBinaryFile('/Users/chilkat/testData/p7b/test.p7b');
  if (success <> True) then
    begin
      WriteLn(asn.LastErrorText);
      Exit;
    end;

  //  Convert ASN.1 to XML:
  strXml := asn.AsnToXml();
  if (asn.LastMethodSuccess <> True) then
    begin
      WriteLn(asn.LastErrorText);
      Exit;
    end;

  //  The XML returned by AsnToXml will be compact and not pretty-formatted.
  //  Use Chilkat XML to format the XML better:
  xml := TXml.Create;
  success := xml.LoadXml(strXml);
  //  Assuming success for this example..
  //  This is formatted better for human viewing:
  WriteLn(xml.GetXml());

  //  Now get the ASN.1 in base64 format.  Any encoding supported
  //  by Chilkat can be passed, such as "hex", "uu", "quoted-printable", "base32", "modbase64", etc.
  strBase64 := asn.GetEncodedDer('base64');

  //  Load the ASN.1 from XML:
  asn2 := TAsn.Create;
  success := asn2.LoadAsnXml(xml.GetXml());
  if (success <> True) then
    begin
      WriteLn(asn2.LastErrorText);
      Exit;
    end;

  //  Load the ASN.1 from an encoded string, such as base64:
  asn3 := TAsn.Create;
  success := asn3.LoadEncoded(strBase64,'base64');
  if (success <> True) then
    begin
      WriteLn(asn3.LastErrorText);
      Exit;
    end;


  asn.Free;
  xml.Free;
  asn2.Free;
  asn3.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.