Pascal (Lazarus/Delphi)

Example for both AES-128 and ChaCha20 to Encrypt Binary Data

See more Encryption Examples

Demonstrates the use of the new EncryptBd and DecryptBd methods introduced in Chilkat v9.5.0.67 to encrypt/decrypt binary bytes.

Note: This example requires Chilkat v9.5.0.67 or greater.

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.BinData,
  Chilkat.Crypt2;

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

procedure RunDemo;
var
  success: Boolean;
  jpgBytes: TBinData;
  crypt: TCrypt2;
  ivHex: string;
  keyHex: string;

begin
  success := False;

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

  //  Load a small JPG file to be encrypted/decrypted.
  jpgBytes := TBinData.Create;
  success := jpgBytes.LoadFile('qa_data/jpg/starfish.jpg');
  if (success <> True) then
    begin
      WriteLn('Failed to load JPG file.');
      Exit;
    end;

  //  Show the unencrypted JPG bytes in Base64 format.
  //  (The "base64_mime" encoding was added in Chilkat v9.5.0.67.
  //  The "base64" encoding emits a single line of base64, whereas
  //  "base64_mime" will emit multi-line base64 as it would appear
  //  in MIME.)
  WriteLn(jpgBytes.GetEncoded('base64_mime'));

  //  Sample base64_mime JPG data:

  //  	/9j/4AAQSkZJRgABAgEASABIAAD/7Q18UGhvdG9zaG9wIDMuMAA4QklNA+0AAAAAABAASAAAAAEA
  //  	AQBIAAAAAQABOEJJTQPzAAAAAAAIAAAAAAAAAAE4QklNBAoAAAAAAAEAADhCSU0nEAAAAAAACgAB
  //  	AAAAAAAAAAI4QklNA/UAAAAAAEgAL2ZmAAEAbGZmAAYAAAAAAAEAL2ZmAAEAoZmaAAYAAAAAAAEA
  //  	MgAAAAEAWgAAAAYAAAAAAAEANQAAAAEALQAAAAYAAAAAAAE4QklNBBQAAAAAAAQAAAABOEJJTQQM
  //  	...

  crypt := TCrypt2.Create;

  //  Specify the encryption to be used.
  //  First we'll do AES-128 CBC
  crypt.CryptAlgorithm := 'aes';
  crypt.CipherMode := 'cbc';
  crypt.KeyLength := 128;

  ivHex := '000102030405060708090A0B0C0D0E0F';
  crypt.SetEncodedIV(ivHex,'hex');

  keyHex := '000102030405060708090A0B0C0D0E0F101112131415161718191A1B1C1D1E1F';
  crypt.SetEncodedKey(keyHex,'hex');

  //  Do the in-place 128-bit AES CBC encryption.
  //  The contents of jpgBytes are replaced with the encrypted bytes.
  success := crypt.EncryptBd(jpgBytes);
  if (success <> True) then
    begin
      WriteLn(crypt.LastErrorText);
      Exit;
    end;

  //  Examine the JPG bytes again.  The bytes should be different because they are encrypted:
  WriteLn(jpgBytes.GetEncoded('base64_mime'));

  //  Sample base64_mime encrypted JPG data:

  //  	sbz0babt1WCkQf5xKMdg/baZAcUBO5GVUUDF2BjVqmd+HrqKN+t6hAcqakL/bdo0q9hYmow0Tp1e
  //  	AQ9V9DOiifQUZqWVkR+kL/c45bq8JGFDvgNl0djPt+yYhV789IB/fPH0upx+/ad++WNOlv1IxGMr
  //  	Y1x1oERU/IsiEzafUJdI4kZ6FQo2IPGMF/Rm1h79I7hP1yYUFxvJyz+PzaySAUH1nLsNHyDVY5VY
  //  	O90aH3steRSYbz8C8UF9wQ3qqEIXQNnnixvoNDnmHyY39VoVBI5F6rnPwYDfAk2t8tmuryFqvwAu
  //  	...

  //  Decrypt to restore back to the original:
  success := crypt.DecryptBd(jpgBytes);
  if (success <> True) then
    begin
      WriteLn(crypt.LastErrorText);
      Exit;
    end;

  WriteLn(jpgBytes.GetEncoded('base64_mime'));

  //  	/9j/4AAQSkZJRgABAgEASABIAAD/7Q18UGhvdG9zaG9wIDMuMAA4QklNA+0AAAAAABAASAAAAAEA
  //  	AQBIAAAAAQABOEJJTQPzAAAAAAAIAAAAAAAAAAE4QklNBAoAAAAAAAEAADhCSU0nEAAAAAAACgAB
  //  	AAAAAAAAAAI4QklNA/UAAAAAAEgAL2ZmAAEAbGZmAAYAAAAAAAEAL2ZmAAEAoZmaAAYAAAAAAAEA
  //  	MgAAAAEAWgAAAAYAAAAAAAEANQAAAAEALQAAAAYAAAAAAAE4QklNBBQAAAAAAAQAAAABOEJJTQQM
  //  	...

  //  ----------------------------------------------------------------------------------
  //  To do chacha20 encryption, just change the settings:

  crypt.CryptAlgorithm := 'chacha20';
  crypt.KeyLength := 256;
  //  The initial count is the initial block counter for the chacha20 algorithm.
  //  It can be any integer, but must be set to the same when decrypting.
  crypt.InitialCount := 22;

  success := crypt.EncryptBd(jpgBytes);
  //  jpgBytes now contains chacha20 encrypted bytes.

  success := crypt.DecryptBd(jpgBytes);
  //  jpgBytes is now restored back to the original unencrypted by bytes.

  //  Save the bytes to a file..
  success := jpgBytes.WriteFile('qa_output/starfish.jpg');

  WriteLn('Success.');


  jpgBytes.Free;
  crypt.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.