Pascal (Lazarus/Delphi)

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.

Pascal (Lazarus/Delphi)

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.