(Delphi ActiveX) Create JWT Using HS256, HS384, or HS512

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

Chilkat for Delphi Downloads Chilkat ActiveX DLL for Delphi Chilkat non-ActiveX DLL for Delphi * The examples here use the ActiveX DLL.

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Chilkat_TLB;

...

procedure TForm1.Button1Click(Sender: TObject);
var
jwt: TChilkatJwt;
jose: TChilkatJsonObject;
success: Integer;
claims: TChilkatJsonObject;
curDateTime: Integer;
strJwt: WideString;

begin
// 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 := TChilkatJwt.Create(Self);

// Build the JOSE header
jose := TChilkatJsonObject.Create(Self);
// 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 := TChilkatJsonObject.Create(Self);
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 := 1;

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

Memo1.Lines.Add(strJwt);
end;