(Delphi ActiveX) JWE using ECDH-ES, BP-256, A256GCM

See more JSON Web Encryption (JWE) Examples

Create a JWE with the following header:

	{
	  "alg": "ECDH-ES",
	  "enc": "A256GCM",
	  "exp": 1621957030,
	  "cty": "NJWT",
	  "epk": {
	    "kty": "EC",
	    "x": "QLpJ_LpFx-6yJhsb4OvHwU1khLnviiOwYOvmf5clK7w"
	    "y": "AJh7pJ3zZKDJkm8rbeG69GBooTosXJgSsvNFH0i3Vxnu"
	    "crv": "BP-256"
	  }
	}

Note: This example requires Chilkat v9.5.0.87 or greater.

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
success: Integer;
json: TChilkatJsonObject;
pubkey: TPublicKey;
jwt: TChilkatJwt;
jweProtHdr: TChilkatJsonObject;
jwe: TChilkatJwe;
plainText: WideString;
strJwe: WideString;

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

// Load our brainpool BP-256 public key.

// 	{
// 	  "use": "enc",
// 	  "kid": "puk_idp_enc",
// 	  "kty": "EC",
// 	  "crv": "BP-256",
// 	  "x": "QLpJ_LpFx-6yJhsb4OvHwU1khLnviiOwYOvmf5clK7w",
// 	  "y": "AJh7pJ3zZKDJkm8rbeG69GBooTosXJgSsvNFH0i3Vxnu"
// 	}

json := TChilkatJsonObject.Create(Self);
json.UpdateString('use','enc');
json.UpdateString('kid','puk_idp_enc');
json.UpdateString('kty','EC');
json.UpdateString('crv','BP-256');
json.UpdateString('x','QLpJ_LpFx-6yJhsb4OvHwU1khLnviiOwYOvmf5clK7w');
json.UpdateString('y','AJh7pJ3zZKDJkm8rbeG69GBooTosXJgSsvNFH0i3Vxnu');

pubkey := TPublicKey.Create(Self);

success := pubkey.LoadFromString(json.Emit());
if (success = 0) then
  begin
    Memo1.Lines.Add(pubkey.LastErrorText);
    Exit;
  end;

// Build our protected header:

// 	{
// 	  "alg": "ECDH-ES",
// 	  "enc": "A256GCM",
// 	  "exp": 1621957030,
// 	  "cty": "NJWT",
// 	  "epk": {
// 	    "kty": "EC",
// 	    "x": "QLpJ_LpFx-6yJhsb4OvHwU1khLnviiOwYOvmf5clK7w"
// 	    "y": "AJh7pJ3zZKDJkm8rbeG69GBooTosXJgSsvNFH0i3Vxnu"
// 	    "crv": "BP-256"
// 	  }
// 	}

// Use jwt only for getting the current date/time + 3600 seconds.
jwt := TChilkatJwt.Create(Self);

jweProtHdr := TChilkatJsonObject.Create(Self);
jweProtHdr.UpdateString('alg','ECDH-ES');
jweProtHdr.UpdateString('enc','A256GCM');
jweProtHdr.UpdateInt('exp',jwt.GenNumericDate(3600));
jweProtHdr.UpdateString('cty','NJWT');
jweProtHdr.UpdateString('epk.kty','EC');
jweProtHdr.UpdateString('epk.x','QLpJ_LpFx-6yJhsb4OvHwU1khLnviiOwYOvmf5clK7w');
jweProtHdr.UpdateString('epk.y','AJh7pJ3zZKDJkm8rbeG69GBooTosXJgSsvNFH0i3Vxnu');
jweProtHdr.UpdateString('epk.crv','BP-256');

jwe := TChilkatJwe.Create(Self);
jwe.SetProtectedHeader(jweProtHdr.ControlInterface);
jwe.SetPublicKey(0,pubkey.ControlInterface);

plainText := 'This is the text to be encrypted.';
strJwe := jwe.Encrypt(plainText,'utf-8');
if (jwe.LastMethodSuccess <> 1) then
  begin
    Memo1.Lines.Add(jwe.LastErrorText);
    Exit;
  end;

Memo1.Lines.Add(strJwe);

Memo1.Lines.Add('Success.');
end;