Pascal (Lazarus/Delphi)

AES XTS Mode

See more Encryption Examples

Demonstrates the AES-XTS mode of operation.

Note: This example requires Chilkat v9.5.0.91 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;
  key: string;
  tweakKey: string;
  dataUnit: string;
  bd: TBinData;
  crypt: TCrypt2;

begin
  success := False;

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

  //  Here we have a sample from CAVS validatition data:

  //  COUNT = 301
  //  DataUnitLen = 200
  //  Key = 
  //  394c97881abd989d29c703e48a72b397
  //  a7acf51b59649eeea9b33274d8541df4
  //  i = 4b15c684a152d485fe9937d39b168c29
  //  PT = 2f3b9dcfbae729583b1d1ffdd16bb6fe2757329435662a78f0
  //  CT = f3473802e38a3ffef4d4fb8e6aa266ebde553a64528a06463e

  //  Note: The above sample requires an AES-XTS implementation that fully supports ciphertext-stealing
  //  because the data to be encrypted is not an even multiple of the AES block size (i.e. not a multiple of 16 bytes).
  //  Chilkat fully supports AES-XTS with ciphertext stealing.
  //  (i.e. Chilkat implements XEX-based tweaked-codebook mode with ciphertext stealing (XTS))

  key := '394c97881abd989d29c703e48a72b397';
  tweakKey := 'a7acf51b59649eeea9b33274d8541df4';
  dataUnit := '4b15c684a152d485fe9937d39b168c29';

  bd := TBinData.Create;
  bd.AppendEncoded('2f3b9dcfbae729583b1d1ffdd16bb6fe2757329435662a78f0','hex');

  crypt := TCrypt2.Create;

  crypt.CryptAlgorithm := 'aes';
  crypt.CipherMode := 'xts';
  crypt.KeyLength := 128;

  crypt.SetEncodedKey(key,'hex');
  crypt.XtsSetEncodedTweakKey(tweakKey,'hex');
  crypt.XtsSetEncodedTweakValue(dataUnit,'hex');

  //  In-place encrypt the contents of bd.
  success := crypt.EncryptBd(bd);

  WriteLn('CT = ' + bd.GetEncoded('hexlower'));

  //  Decrypt to revert back to the unencrypted content:
  success := crypt.DecryptBd(bd);

  WriteLn('PT = ' + bd.GetEncoded('hexlower'));

  //  Output:
  //  CT = f3473802e38a3ffef4d4fb8e6aa266ebde553a64528a06463e
  //  PT = 2f3b9dcfbae729583b1d1ffdd16bb6fe2757329435662a78f0


  bd.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.