Load and Validate a JWS from a StringBuilder

See more JSON Web Signatures (JWS) Examples

Demonstrates Jws.LoadJwsSb, which loads a JWS from a StringBuilder (here read from a file). The example then supplies the MAC key and validates the signature.

The file path is relative to the application's current working directory. An absolute path may also be used. Supply the path appropriate to your own environment.

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.Jws,
  Chilkat.StringBuilder;

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

procedure RunDemo;
var
  success: Boolean;
  jws: TJws;
  sbJws: TStringBuilder;
  bLoaded: Boolean;
  base64Key: string;
  v: Integer;

begin
  success := False;

  jws := TJws.Create;

  //  The file path is relative to the application's current working directory.  An absolute path may
  //  also be used.  Supply the path appropriate to your own environment.

  //  Load the JWS text from a file into a StringBuilder.
  sbJws := TStringBuilder.Create;
  bLoaded := sbJws.LoadFile('qa_data/message.jws','utf-8');
  if (bLoaded <> True) then
    begin
      WriteLn('Failed to load the JWS file.');
      Exit;
    end;

  //  Load the JWS from the StringBuilder.
  success := jws.LoadJwsSb(sbJws);
  if (success = False) then
    begin
      WriteLn(jws.LastErrorText);
      Exit;
    end;

  base64Key := 'YWJjZGVmZ2hpamtsbW5vcHFyc3R1dnd4eXowMTIzNDU=';
  success := jws.SetMacKey(0,base64Key,'base64');
  if (success = False) then
    begin
      WriteLn(jws.LastErrorText);
      Exit;
    end;

  v := jws.Validate(0);
  if (v < 0) then
    begin
      WriteLn(jws.LastErrorText);
      Exit;
    end;
  if (v <> 1) then
    begin
      WriteLn('The signature is not valid.');
      Exit;
    end;
  WriteLn('The signature is valid.');


  jws.Free;
  sbJws.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.