Pascal (Lazarus/Delphi)

Create JWT using Smart Card

See more JSON Web Token (JWT) Examples

Demonstrates how to create a JWT using an RSA private key and certificate on a smart card. This is for JOSE headers with an "alg" of RS256, RS384, or RS512. When RSA is used, the private key signs (creates) the JWT, and the public key is for verification.

This example also demonstrates how to include time constraints:

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

Note: This example requires Chilkat v9.5.0.99 or later.

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.Jwt,
  Chilkat.JsonObject,
  Chilkat.Cert;

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

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

begin
  success := False;

  //  Demonstrates how to create a JWT using an RSA private key and certificate on a smart card.

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

  jwt := TJwt.Create;
  cert := TCert.Create;

  success := cert.LoadFromSmartcard('');
  if (success = False) then
    begin
      WriteLn(cert.LastErrorText);
      Exit;
    end;

  //  Build the JOSE header
  jose := TJsonObject.Create;
  //  Use RS256.  Pass the string "RS384" or "RS512" to use RSA with SHA-384 or SHA-512.
  jose.UpdateString('alg','RS256');
  jose.UpdateString('typ','JWT');
  jose.UpdateString('x5c[0]',cert.GetEncoded());

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

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

  //  Set the "not process before" timestamp to now.
  claims.UpdateInt('nbf',curDateTime);

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

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

  //  Create the JWT token.  This is where the RSA signature is created.
  token := jwt.CreateJwtCert(jose.Emit(),claims.Emit(),cert);

  WriteLn(token);


  jwt.Free;
  cert.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.