Pascal (Lazarus/Delphi)

Create JWT Using HS256, HS384, or HS512

See more JSON Web Token (JWT) Examples

Demonstrates how to create a JWT using HS256, HS384, or HS512. (HS256 is JWT's acronym for HMAC-SHA256.) When HMAC is used, the secret is a shared secret (i.e. password) that both client and server know beforehand.

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.JsonObject,
  Chilkat.Jwt;

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

procedure RunDemo;
var
  success: Boolean;
  jwt: TJwt;
  jose: TJsonObject;
  claims: TJsonObject;
  curDateTime: Integer;
  strJwt: string;

begin
  success := False;

  //  Demonstrates how to create an HMAC JWT using a shared secret (password).

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

  jwt := TJwt.Create;

  //  Build the JOSE header
  jose := TJsonObject.Create;
  //  Use HS256.  Pass the string "HS384" or "HS512" to use a different algorithm.
  success := jose.AppendString('alg','HS256');
  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;

  strJwt := jwt.CreateJwt(jose.Emit(),claims.Emit(),'secret');

  WriteLn(strJwt);


  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.