(Delphi DLL) Get ECC Public Key in JWK Format (JSON Web Key)

Demonstrates how to get an ECC public key in JWK (JSON Web Key) format.

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

Chilkat for Delphi Downloads Chilkat non-ActiveX DLL for Delphi Chilkat ActiveX DLL for Delphi * The examples here use the non-ActiveX DLL.

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

...

procedure TForm1.Button1Click(Sender: TObject);
var
sbPem: HCkStringBuilder;
success: Boolean;
pubKey: HCkPublicKey;
jwk: PWideChar;
json: HCkJsonObject;

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

// Load a PEM file into memory.
sbPem := CkStringBuilder_Create();
success := CkStringBuilder_LoadFile(sbPem,'qa_data/pem/ecc_public.pem','utf-8');
if (success <> True) then
  begin
    Memo1.Lines.Add('Failed to load PEM file.');
    Exit;
  end;

// Load the PEM into a public key object.
pubKey := CkPublicKey_Create();
success := CkPublicKey_LoadFromString(pubKey,CkStringBuilder__getAsString(sbPem));
if (success <> True) then
  begin
    Memo1.Lines.Add(CkPublicKey__lastErrorText(pubKey));
    Exit;
  end;

// Get the public key in JWK format:
jwk := CkPublicKey__getJwk(pubKey);

// The GetJwk method will return the JWK in the most compact JSON format possible,
// as a single line with no extra whitespace.  To get a more human-readable JWK (for this example),
// load into a Chilkat JSON object and emit non-compact:

json := CkJsonObject_Create();
CkJsonObject_Load(json,jwk);
CkJsonObject_putEmitCompact(json,False);
Memo1.Lines.Add('ECC Public Key in JWK format:');
Memo1.Lines.Add(CkJsonObject__emit(json));

// Sample output:
// { 
//   "kty": "EC",
//   "crv": "P-256",
//   "x": "oBUyo8CQAFPeYPvv78ylh5MwFZjTCLQeb042TjiMJxE",
//   "y": "vvQyxZkUjJQUPU_0bCy3Pj5qQdfu8jwEfqEeYGZ95CU"
// }
// 
// Additional information can be added like this:
CkJsonObject_AppendString(json,'use','enc');
CkJsonObject_AppendString(json,'kid','123ABC');

// Now examine the JSON:
Memo1.Lines.Add(CkJsonObject__emit(json));

// { 
//   "kty": "EC",
//   "crv": "P-256",
//   "x": "oBUyo8CQAFPeYPvv78ylh5MwFZjTCLQeb042TjiMJxE",
//   "y": "vvQyxZkUjJQUPU_0bCy3Pj5qQdfu8jwEfqEeYGZ95CU",
//   "use": "enc",
//   "kid": "123ABC"
// }

CkStringBuilder_Dispose(sbPem);
CkPublicKey_Dispose(pubKey);
CkJsonObject_Dispose(json);

end;