(Delphi ActiveX) Load ECC Public Key from JWK Format (JSON Web Key)

Demonstrates how to load an ECC public key from JWK (JSON Web Key) format.

Note: This example requires Chilkat v9.5.0.66 or later.

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;
jwkStr: WideString;
pubKey: TPublicKey;
bPreferPkcs1: Integer;

begin
// Note: This example requires Chilkat v9.5.0.66 or later.

// First build a JWK sample to load..
json := TChilkatJsonObject.Create(Self);
json.UpdateString('kty','EC');
json.UpdateString('crv','P-256');
json.UpdateString('x','oBUyo8CQAFPeYPvv78ylh5MwFZjTCLQeb042TjiMJxE');
json.UpdateString('y','vvQyxZkUjJQUPU_0bCy3Pj5qQdfu8jwEfqEeYGZ95CU');

// The JSON contains the following:
// { 
//   "kty": "EC",
//   "crv": "P-256",
//   "x": "oBUyo8CQAFPeYPvv78ylh5MwFZjTCLQeb042TjiMJxE",
//   "y": "vvQyxZkUjJQUPU_0bCy3Pj5qQdfu8jwEfqEeYGZ95CU",
// }

// Note: The JSON can contain other members, such as "use", "kid", or anything else.  These will be ignored.
json.EmitCompact := 0;

// Show the JWK string to be loaded:
jwkStr := json.Emit();

pubKey := TPublicKey.Create(Self);
// The LoadFromString method will automatically detect the format.
success := pubKey.LoadFromString(jwkStr);
if (success <> 1) then
  begin
    Memo1.Lines.Add(pubKey.LastErrorText);
    Exit;
  end;

// OK.. the JWK is loaded.  It can be used in whatever way desired...

// The key can be retrieved in any other format, such as XML or PEM..
Memo1.Lines.Add(pubKey.GetXml());

// XML output:
// <ECCPublicKey curve="secp256r1" 
//    x="A01532A3C0900053DE60FBEFEFCCA58793301598D308B41E6F4E364E388C2711" 
//    y="BEF432C599148C94143D4FF46C2CB73E3E6A41D7EEF23C047EA11E60667DE425">
//    MIIBSzCCAQMGByqGSM49AgEwgfcCAQEwLAYHKoZIzj0BAQIhAP////8AAAABAAAAAAAAAAAAAAAA////////////////MFsEIP////8AAAABAAAAAAAAAAAAAAAA///////////////8BCBaxjXYqjqT57PrvVV2mIa8ZR0GsMxTsPY7zjw+J9JgSwMVAMSdNgiG5wSTamZ44ROdJreBn36QBEEEaxfR8uEsQkf4vOblY6RA8ncDfYEt6zOg9KE5RdiYwpZP40Li/hp/m47n60p8D54WK84zV2sxXs7LtkBoN79R9QIhAP////8AAAAA//////////+85vqtpxeehPO5ysL8YyVRAgEBA0IABKAVMqPAkABT3mD77+/MpYeTMBWY0wi0Hm9ONk44jCcRvvQyxZkUjJQUPU/0bCy3Pj5qQdfu8jwEfqEeYGZ95CU=
// </ECCPublicKey>

// Choose PCKS1 or PCKS8 PEM format..
bPreferPkcs1 := 0;
Memo1.Lines.Add(pubKey.GetPem(bPreferPkcs1));

// PEM output
// -----BEGIN PUBLIC KEY-----
// MIIBSzCCAQMGByqGSM49AgEwgfcCAQEwLAYHKoZIzj0BAQIhAP////8AAAABAAAA
// AAAAAAAAAAAA////////////////MFsEIP////8AAAABAAAAAAAAAAAAAAAA////
// ///////////8BCBaxjXYqjqT57PrvVV2mIa8ZR0GsMxTsPY7zjw+J9JgSwMVAMSd
// NgiG5wSTamZ44ROdJreBn36QBEEEaxfR8uEsQkf4vOblY6RA8ncDfYEt6zOg9KE5
// RdiYwpZP40Li/hp/m47n60p8D54WK84zV2sxXs7LtkBoN79R9QIhAP////8AAAAA
// //////////+85vqtpxeehPO5ysL8YyVRAgEBA0IABKAVMqPAkABT3mD77+/MpYeT
// MBWY0wi0Hm9ONk44jCcRvvQyxZkUjJQUPU/0bCy3Pj5qQdfu8jwEfqEeYGZ95CU=
// -----END PUBLIC KEY-----
end;