Lazarus Pascal

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.

Lazarus Pascal

program ChilkatDemo;

// Demonstrates using the Chilkat Pascal wrapper via the C bridge DLL.
// Builds as a console application under Lazarus (FPC) or Delphi.

{$IFDEF FPC}
  {$MODE DELPHI}
{$ENDIF}
{$APPTYPE CONSOLE}

uses
  {$IFDEF UNIX}
  cthreads,
  {$ENDIF}
  SysUtils,
  CkDllLoader,
  Chilkat.JsonObject,
  Chilkat.PublicKey;

// ---------------------------------------------------------------------------

procedure RunDemo;
var
  success: Boolean;
  json: TJsonObject;
  jwkStr: string;
  pubKey: TPublicKey;
  bPreferPkcs1: Boolean;

begin
  success := False;

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

  //  First build a JWK sample to load..
  json := TJsonObject.Create;
  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 := False;

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

  pubKey := TPublicKey.Create;
  //  The LoadFromString method will automatically detect the format.
  success := pubKey.LoadFromString(jwkStr);
  if (success <> True) then
    begin
      WriteLn(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..
  WriteLn(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 := False;
  WriteLn(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-----


  json.Free;
  pubKey.Free;

end;

// ---------------------------------------------------------------------------

begin

  try
    RunDemo;
  except
    on E: Exception do
      WriteLn('Unhandled exception: ', E.ClassName, ': ', E.Message);
  end;

  WriteLn;
  {$IFDEF MSWINDOWS}
  WriteLn('Press Enter to exit...');
  ReadLn;
  {$ENDIF}
end.