Hash a Password with Argon2 (Tuned Options)

Demonstrates Crypt2.Argon2HashPassword with explicit options: the cost parameters, saltLen (how many random salt bytes to generate when no salt is given), and an optional secret (pepper).

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.Crypt2,
  Chilkat.JsonObject;

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

procedure RunDemo;
var
  crypt: TCrypt2;
  password: string;
  json: TJsonObject;
  phcHash: string;

begin
  crypt := TCrypt2.Create;

  //  The password should come from a secure source rather than being hard-coded.
  password := 'correct horse battery staple';

  //  The Argon2 options are the same members as Argon2DeriveKey, except the salt is optional for
  //  hashing.  When no "salt" is given, a random salt is generated; "saltLen" (default 16, range 8..1024)
  //  sets how many random bytes to use.
  json := TJsonObject.Create;
  json.UpdateString('variant','argon2id');
  json.UpdateInt('memoryCostKb',131072);
  json.UpdateInt('iterations',4);
  json.UpdateInt('parallelism',2);
  json.UpdateInt('saltLen',16);

  //  A secret (pepper) and/or ad may be used, but neither is stored in the returned PHC string.  The
  //  same values must be supplied to Argon2VerifyPassword for the password to verify.
  json.UpdateString('secret','application-wide-pepper');
  json.UpdateString('secretEncoding','utf-8');

  phcHash := crypt.Argon2HashPassword(password,json.Emit());
  if (crypt.LastMethodSuccess = False) then
    begin
      WriteLn(crypt.LastErrorText);
      Exit;
    end;
  WriteLn(phcHash);


  crypt.Free;
  json.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.