(Delphi DLL) Create JWT Using ECC (ES256, ES384, or ES512)

Demonstrates how to create a JWT using an ECC private key. This is for JOSE headers with an "alg" of ES256, ES384, or ES512. When ECC 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

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

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

...

procedure TForm1.Button1Click(Sender: TObject);
var
privKey: HCkPrivateKey;
success: Boolean;
jwt: HCkJwt;
jose: HCkJsonObject;
claims: HCkJsonObject;
curDateTime: Integer;
token: PWideChar;

begin
// Demonstrates how to create a JWT using an ECC private key.

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

privKey := CkPrivateKey_Create();

// Load an ECC private key from a PEM file.
success := CkPrivateKey_LoadPemFile(privKey,'qa_data/pem/ecc_privKey.pem');
if (success <> True) then
  begin
    Memo1.Lines.Add(CkPrivateKey__lastErrorText(privKey));
    Exit;
  end;

jwt := CkJwt_Create();

// Build the JOSE header
jose := CkJsonObject_Create();
// Use ES256.  Pass the string "ES384" or "ES512" to use ECC with SHA-384 or SHA-512.
success := CkJsonObject_AppendString(jose,'alg','ES256');
success := CkJsonObject_AppendString(jose,'typ','JWT');

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

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

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

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

// Produce the smallest possible JWT:
CkJwt_putAutoCompact(jwt,True);

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

Memo1.Lines.Add(token);

// Example output:
// eyJhbGciOiJFUzI1NiIsInR5cCI6IkpXVCJ9.eyJpc3MiOiJodHRwOi8vZXhhbXBsZS5vcmciLCJzdWIiOiJKb2huIiwiYXVkIjoiaHR0cDovL2V4YW1wbGUuY29tIiwiaWF0IjoxNDg1NzA4NzkyLCJuYmYiOjE0ODU3MDg3OTIsImV4cCI6MTQ4NTcxMjM5Mn0.wqsuyJpxJ073ox-lOiLFqG1lQocXe4hGf2XGZJRrO3qn0UusxI_bu3Gzky8gBsH4sA4u9TWZn5M-1wYMMIJk6Q

CkPrivateKey_Dispose(privKey);
CkJwt_Dispose(jwt);
CkJsonObject_Dispose(jose);
CkJsonObject_Dispose(claims);

end;