DEC 6.0 Salzstreuer

[Klapauzius]

Danke, dann habe ich Salt jetzt verstanden.

Hier meine Testklasse zur Textverschlüsselung:
Sieht das so sicherheitstechnisch korrekt aus?

Delphi-Quellcode:

unit Unit2;

interface

uses
  System.SysUtils, System.TypInfo, Generics.Collections, FMX.Platform,
  DECCipherBase, DECFormatBase, DECBaseClass, DECFormat, DECCipherModes,
  DECCipherFormats, DECCiphers, DECUtil, DECHashBase, DECHash, DECRandom,
  System.Classes, FMX.Dialogs;

type
  DECEnc = class(TObject)
  private
    Cipher: TCipher_AES;
    FFiller: Byte;
    FIV: TBytes;
    FPassword: UTF8String;
    function GenerateHashedPw: TBytes;
    procedure SetPassword(const Value: UTF8String);

  public
    constructor Create;
    property Password: UTF8String read FPassword write SetPassword;
    destructor Destroy; override;
    function DecryptString(ENC_Base64String: UTF8String): UTF8String;
    function EncryptString(const PlainText: UTF8String): UTF8String;

  end;

implementation
 
constructor DECEnc.Create;
begin
  inherited;
    FIV:= TEncoding.UTF8.GetBytes('2A7Q5!8;');
    RandomBuffer(FFiller,4);
    Cipher:= TCipher_AES.Create;
    Cipher.Mode := cmCBCx;

end;

destructor DECEnc.Destroy;
begin
  cipher.Free;
  inherited;

end;

function DECEnc.DecryptString(ENC_Base64String: UTF8String): UTF8String;
var
 output: TBytes;
 DecodedString: UTF8String;
 input: TBytes;
begin
    Cipher.Init(GenerateHashedPw,FIV,FFiller);
    Input  := System.SysUtils.BytesOf(ENC_Base64String);
    output := Cipher.DecodeBytes(TFormat_Base64.decode(Input));
    result:= TEncoding.UTF8.GetString(output);
end;

function DECEnc.EncryptString(const PlainText: UTF8String): UTF8String;
var
  output: utf8String;
  Data:TBytes;
begin
    Cipher.Init(GenerateHashedPw,FIV,FFiller);
    output:= UTF8Encode(Cipher.EncodeStringToString(PlainText, TFormat_BASE64));
    result:= output;
end;

function DECEnc.GenerateHashedPw: TBytes;
var
  Hash: THash_SHA256;
  Salt: utf8string;
  SaltBytes: TBytes;
  PW: TBytes;
  HashedPw: TBytes;
begin
  Salt:=  'wer 9845747 198498 34534';
  Hash:= THash_SHA256.create;
  try
   SaltBytes:= TEncoding.utf8.GetBytes(Salt);
   PW:=  TEncoding.utf8.GetBytes(FPassword);
   HashedPw:= Hash.KDF1(PW,SaltBytes,Cipher.Context.KeySize);
   result:= HashedPw;
  finally
     Hash.Free;
  end;

end;

procedure DECEnc.SetPassword(const Value: UTF8String);
begin
  FPassword := Value;
end;

end.