Pascal (Lazarus/Delphi)

How to Parse a X.509 Certificate and Extract its Public Key

See more Certificates Examples

Demonstrates how to load an X.509 certificate and extract the public key. Chilkat supports many certificate encodings:

• DER (binary) encoded certificates (.crt/.cer)
• PEM (BASE64) encoded certificates (.pem)
• Load Certificates Directly from Windows Certificate Stores
• PFX/PKCS12 (.pfx/.p12)
• Java KeyStore (.jks)
• Cryptographic Message Syntax Standard - PKCS #7 Certificates (.P7B)

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.Cert,
  Chilkat.PublicKey;

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

procedure RunDemo;
var
  success: Boolean;
  cert: TCert;
  pubKey: TPublicKey;

begin
  success := False;

  cert := TCert.Create;

  //  Load a DER (binary) encoded certificate.
  //  To load from a .pem or .p7b, or any other file format that contains
  //  just one certificate, call LoadFromFile in exactly the same way.
  //  The LoadFromFile method automatically detects the format and loads the certificate.
  success := cert.LoadFromFile('qa_data/certs/testCert.cer');
  if (success = False) then
    begin
      WriteLn(cert.LastErrorText);
      Exit;
    end;

  //  Get the public key:
  pubKey := TPublicKey.Create;
  cert.GetPublicKey(pubKey);

  //  Examine the key type.
  //  A PublicKey object can contain an RSA, ECC, or DSA public key.
  //  The KeyType property will contain "rsa", "ecc", or "dsa".
  WriteLn('key type = ' + pubKey.KeyType);


  cert.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.