Delphi DLL

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

See more ECC Examples

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.

Delphi DLL

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

...

procedure TForm1.Button1Click(Sender: TObject);
var
success: Boolean;
json: HCkJsonObject;
jwkStr: PWideChar;
pubKey: HCkPublicKey;
bPreferPkcs1: Boolean;

begin
success := False;

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

// First build a JWK sample to load..
json := CkJsonObject_Create();
CkJsonObject_UpdateString(json,'kty','EC');
CkJsonObject_UpdateString(json,'crv','P-256');
CkJsonObject_UpdateString(json,'x','oBUyo8CQAFPeYPvv78ylh5MwFZjTCLQeb042TjiMJxE');
CkJsonObject_UpdateString(json,'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.
CkJsonObject_putEmitCompact(json,False);

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

pubKey := CkPublicKey_Create();
// The LoadFromString method will automatically detect the format.
success := CkPublicKey_LoadFromString(pubKey,jwkStr);
if (success <> True) then
  begin
    Memo1.Lines.Add(CkPublicKey__lastErrorText(pubKey));
    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(CkPublicKey__getXml(pubKey));

// 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 := False;
Memo1.Lines.Add(CkPublicKey__getPem(pubKey,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-----

CkJsonObject_Dispose(json);
CkPublicKey_Dispose(pubKey);

end;