Pascal (Lazarus/Delphi)

Encrypt File using X.509 Certificate using AES in CBC Mode

See more Encryption Examples

Demonstrates how to encrypt a file using an X.509 Certificate's public key, where the underlying bulk encryption algorithm is 128-bit AES in CBC mode. (The underlying bulk encryption algorithm can be specified to be other algorithms/strengths.) 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.Crypt2;

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

procedure RunDemo;
var
  success: Boolean;
  crypt: TCrypt2;
  cert: TCert;

begin
  success := False;

  //  This example requires the Chilkat API to have been previously unlocked.
  //  See Global Unlock Sample for sample code.

  crypt := TCrypt2.Create;

  //  Use public-key cryptography for encryption.
  crypt.CryptAlgorithm := 'pki';

  //  Get an X.509 certificate to use for encrypting.
  //  Note: Chilkat provides many different ways of loading a certificate, from many different formats,
  //  or if on Windows, from the installed certificates on the system.
  //  This example simply loads a certificate from a file.
  //  Also, for encryption, only the public key is needed.  Digital certificates embed the public key
  //  within the X.509 format itself.  Therefore, if you have a certificate, you also have the public key.
  cert := TCert.Create;
  success := cert.LoadFromFile('qa_data/certs/testCert.cer');
  if (success <> True) then
    begin
      WriteLn(cert.LastErrorText);
      Exit;
    end;

  success := crypt.SetEncryptCert(cert);
  if (success <> True) then
    begin
      WriteLn(crypt.LastErrorText);
      Exit;
    end;

  //  Indicate the underlying bulk encryption algorithm to be used:
  crypt.Pkcs7CryptAlg := 'aes';
  crypt.KeyLength := 128;

  //  Note: When doing public-key encryption the underlying bulk symmetric cipher mode will always be CBC. (at least with Chilkat...)

  //  There's one last option that could be set.  If is the RSA encryption encryption/padding scheme. 
  //  By default, RSAES_PKCS1-V1_5 is used.  If desired, the OaepPadding property could be set to True to
  //  use RSAES_OAEP.  (We'll leave it set at the default value of False)
  crypt.OaepPadding := False;

  //  Everything is specified.  Now just encrypt...
  //  The output is PKCS7 in binary DER format.
  success := crypt.CkEncryptFile('qa_data/hamlet.xml','qa_output/hamlet.p7');
  if (success <> True) then
    begin
      WriteLn(crypt.LastErrorText);
      Exit;
    end;

  WriteLn('Finished.');


  crypt.Free;
  cert.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.