Pascal (Lazarus/Delphi)

Create JWT using a Brainpool EC Key

See more JSON Web Token (JWT) Examples

Demonstrates how to create a JWT using an EC private key. This is for JOSE headers having an "alg" member with any of the following values:

• BP160R1
• BP192R1
• BP224R1
• BP256R1
• BP320R1
• BP384R1
• BP512R1

This example also demonstrates how to include time constraints:

• nbf: Not Before Time
• exp: Expiration Time
• iat: Issue At Time

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.PrivateKey,
  Chilkat.Jwt,
  Chilkat.JsonObject;

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

procedure RunDemo;
var
  success: Boolean;
  privKey: TPrivateKey;
  jwt: TJwt;
  jose: TJsonObject;
  claims: TJsonObject;
  curDateTime: Integer;
  token: string;

begin
  success := False;

  //  Demonstrates how to create a JWT using a brainpool EC private key.

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

  privKey := TPrivateKey.Create;

  //  Load a brainpool EC key.
  success := privKey.LoadPemFile('c:/qa_data/pem/ec_brainpool_privKey.pem');
  if (success <> True) then
    begin
      WriteLn(privKey.LastErrorText);
      Exit;
    end;

  //  You can examine the curve name of the key you just loaded by getting the private in XML format:
  //  <ECCKeyValue curve="CURVE_NAME">...</ECCKeyValue>
  WriteLn(privKey.GetXml());

  jwt := TJwt.Create;

  //  Build the JOSE header
  jose := TJsonObject.Create;
  //  Use the brainpool curve name matching the private key you just loaded.
  //  Use "BP256R1", or "BP384R1", etc.   
  success := jose.AppendString('alg','BP256R1');
  success := jose.AppendString('typ','JWT');

  //  Now build the JWT claims (also known as the payload)
  claims := TJsonObject.Create;
  success := claims.AppendString('iss','http://example.org');
  success := claims.AppendString('sub','John');
  success := claims.AppendString('aud','http://example.com');

  //  Set the timestamp of when the JWT was created to now.
  curDateTime := jwt.GenNumericDate(0);
  success := claims.AddIntAt(-1,'iat',curDateTime);

  //  Set the "not process before" timestamp to now.
  success := claims.AddIntAt(-1,'nbf',curDateTime);

  //  Set the timestamp defining an expiration time (end time) for the token
  //  to be now + 1 hour (3600 seconds)
  success := claims.AddIntAt(-1,'exp',curDateTime + 3600);

  //  Produce the smallest possible JWT:
  jwt.AutoCompact := True;

  //  Create the JWT token.  This is where the ECC signature is created.
  token := jwt.CreateJwtPk(jose.Emit(),claims.Emit(),privKey);

  WriteLn(token);


  privKey.Free;
  jwt.Free;
  jose.Free;
  claims.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.