Pascal (Lazarus/Delphi)

Get RSA Public Key in JWK Format (JSON Web Key)

See more JSON Web Signatures (JWS) Examples

Demonstrates how to get an RSA public key in 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.StringBuilder,
  Chilkat.PublicKey,
  Chilkat.JsonObject;

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

procedure RunDemo;
var
  success: Boolean;
  sbPem: TStringBuilder;
  pubKey: TPublicKey;
  jwk: string;
  json: TJsonObject;

begin
  success := False;

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

  //  Load a PEM file into memory.
  sbPem := TStringBuilder.Create;
  success := sbPem.LoadFile('qa_data/pem/rsa_public.pem','utf-8');
  if (success <> True) then
    begin
      WriteLn('Failed to load PEM file.');
      Exit;
    end;

  //  Load the PEM into a public key object.
  pubKey := TPublicKey.Create;
  success := pubKey.LoadFromString(sbPem.GetAsString());
  if (success <> True) then
    begin
      WriteLn(pubKey.LastErrorText);
      Exit;
    end;

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

  //  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 := TJsonObject.Create;
  json.Load(jwk);
  json.EmitCompact := False;
  WriteLn('RSA Public Key in JWK format:');
  WriteLn(json.Emit());

  //  Sample output:
  //  { 
  //    "kty": "RSA",
  //    "n": "33TqqLR3eeUmDtHS89qF3p4MP7Wfqt2Zjj3lZjLjjCGDvwr9cJNlNDiuKboODgUiT4ZdPWbOiMAfDcDzlOxA04DDnEFGAf-kDQiNSe2ZtqC7bnIc8-KSG_qOGQIVaay4Ucr6ovDkykO5Hxn7OU7sJp9TP9H0JH8zMQA6YzijYH9LsupTerrY3U6zyihVEDXXOv08vBHk50BMFJbE9iwFwnxCsU5-UZUZYw87Uu0n4LPFS9BT8tUIvAfnRXIEWCha3KbFWmdZQZlyrFw0buUEf0YN3_Q0auBkdbDR_ES2PbgKTJdkjc_rEeM0TxvOUf7HuUNOhrtAVEN1D5uuxE1WSw",
  //    "e": "AQAB"
  //  }

  //  Additional information can be added like this:
  json.AppendString('use','enc');
  json.AppendString('kid','123ABC');

  //  Now examine the JSON:
  WriteLn(json.Emit());

  //  { 
  //    "kty": "RSA",
  //    "n": "33TqqLR3eeUmDtHS89qF3p4MP7Wfqt2Zjj3lZjLjjCGDvwr9cJNlNDiuKboODgUiT4ZdPWbOiMAfDcDzlOxA04DDnEFGAf-kDQiNSe2ZtqC7bnIc8-KSG_qOGQIVaay4Ucr6ovDkykO5Hxn7OU7sJp9TP9H0JH8zMQA6YzijYH9LsupTerrY3U6zyihVEDXXOv08vBHk50BMFJbE9iwFwnxCsU5-UZUZYw87Uu0n4LPFS9BT8tUIvAfnRXIEWCha3KbFWmdZQZlyrFw0buUEf0YN3_Q0auBkdbDR_ES2PbgKTJdkjc_rEeM0TxvOUf7HuUNOhrtAVEN1D5uuxE1WSw",
  //    "e": "AQAB",
  //    "use": "enc",
  //    "kid": "123ABC"
  //  }


  sbPem.Free;
  pubKey.Free;
  json.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.