Pascal (Lazarus/Delphi)

Get a Certificate's Key Size

See more Certificates Examples

Demonstrates how to get the RSA key size of a certificate (for example, 1024-bit, 2048-bit, etc.) 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.Xml,
  Chilkat.StringBuilder,
  Chilkat.BinData,
  Chilkat.Cert,
  Chilkat.PublicKey;

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

procedure RunDemo;
var
  success: Boolean;
  sbCertBase64: TStringBuilder;
  cert: TCert;
  pubKey: TPublicKey;
  numBits: Integer;
  xml: TXml;
  binDat: TBinData;

begin
  success := False;

  //  For this example, I have a certificate in raw base64 format (not PEM),
  //  that looks like this:  "MIIGkDCCBHigAwIBAgIUMDA ... s/iqLsLA=="
  sbCertBase64 := TStringBuilder.Create;
  success := sbCertBase64.LoadFile('qa_data/certs/base64Cert.txt','utf-8');

  cert := TCert.Create;
  success := cert.LoadFromBase64(sbCertBase64.GetAsString());
  if (success = False) then
    begin
      WriteLn(cert.LastErrorText);
      Exit;
    end;

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

  numBits := pubKey.KeySize;
  WriteLn('Number of bits = ' + numBits);

  //  If using an older version of Chilkat, the key size can be obtained like this:
  xml := TXml.Create;
  xml.LoadXml(pubKey.GetXml());

  binDat := TBinData.Create;
  binDat.AppendEncoded(xml.GetChildContent('Modulus'),'base64');

  numBits := 8 * binDat.NumBytes;
  WriteLn('Number of bits = ' + numBits);


  sbCertBase64.Free;
  cert.Free;
  pubKey.Free;
  xml.Free;
  binDat.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.