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Pascal (Lazarus/Delphi)

Set the Optional JWS Unprotected Header

See more JSON Web Signatures (JWS) Examples

Demonstrates Jws.SetUnprotectedHeader, which sets the optional unprotected header for a signature.

Background. Unlike the protected header, the unprotected header is not covered by the signature. It is carried in the JSON serialization forms of a JWS, so producing a JWS with an unprotected header yields a JSON serialization rather than compact form.

Chilkat Pascal (Lazarus/Delphi) Downloads

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.Jws,
  Chilkat.JsonObject;

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

procedure RunDemo;
var
  success: Boolean;
  jws: TJws;
  header: TJsonObject;
  unprotected: TJsonObject;
  bIncludeBom: Boolean;
  base64Key: string;
  jwsJson: string;

begin
  success := False;

  jws := TJws.Create;

  //  Protected header specifying HMAC-SHA256.
  header := TJsonObject.Create;
  header.UpdateString('alg','HS256');
  success := jws.SetProtectedHeader(0,header);
  if (success = False) then
    begin
      WriteLn(jws.LastErrorText);
      Exit;
    end;

  //  Set the optional unprotected header for signature 0.  Unlike the protected header, it is not
  //  covered by the signature.  It is carried in the JSON serialization forms of a JWS.
  unprotected := TJsonObject.Create;
  unprotected.UpdateString('kid','signer-key-1');
  success := jws.SetUnprotectedHeader(0,unprotected);
  if (success = False) then
    begin
      WriteLn(jws.LastErrorText);
      Exit;
    end;

  bIncludeBom := False;
  success := jws.SetPayload('This is the content to sign.','utf-8',bIncludeBom);
  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;

  //  Because an unprotected header is present, the JWS is produced in a JSON serialization form.
  jwsJson := jws.CreateJws();
  if (jws.LastMethodSuccess = False) then
    begin
      WriteLn(jws.LastErrorText);
      Exit;
    end;
  WriteLn(jwsJson);


  jws.Free;
  header.Free;
  unprotected.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.