AES Verschlüsselung

[DLX]

Hallo,

ich möchte Strings mit AES verschlüsseln

habe folgendes gefunden:

Code:

unit cryptoUtils;

interface

function AES128_Encrypt(Value, Password: string): string;
function AES128_Decrypt(Value, Password: string): string;

implementation

uses
  SysUtils, Windows, IdCoderMIME, IdGlobal;

//-------------------------------------------------------------------------------------------------------------------------
//    Base64 Encode/Decode
//-------------------------------------------------------------------------------------------------------------------------

function Base64_Encode(Value: TBytes): string;
var
  Encoder: TIdEncoderMIME;
begin
  Encoder := TIdEncoderMIME.Create(nil);
  try
    Result := Encoder.EncodeBytes(TIdBytes(Value));
  finally
    Encoder.Free;
  end;
end;

function Base64_Decode(Value: string): TBytes;
var
  Encoder: TIdDecoderMIME;
begin
  Encoder := TIdDecoderMIME.Create(nil);
  try
    Result := TBytes(Encoder.DecodeBytes(Value));
  finally
    Encoder.Free;
  end;
end;

//-------------------------------------------------------------------------------------------------------------------------
//    WinCrypt.h
//-------------------------------------------------------------------------------------------------------------------------

type
  HCRYPTPROV  = Cardinal;
  HCRYPTKEY   = Cardinal;
  ALG_ID      = Cardinal;
  HCRYPTHASH  = Cardinal;

const
  _lib_ADVAPI32    = 'ADVAPI32.dll';
  CALG_SHA_256     = 32780;
  CALG_AES_128     = 26126;
  CRYPT_NEWKEYSET  = $00000008;
  PROV_RSA_AES     = 24;
  KP_MODE          = 4;
  CRYPT_MODE_CBC   = 1;

function CryptAcquireContext(var Prov: HCRYPTPROV; Container: PChar; Provider: PChar; ProvType: LongWord; Flags: LongWord): LongBool; stdcall; external _lib_ADVAPI32 name 'CryptAcquireContextW';
function CryptDeriveKey(Prov: HCRYPTPROV; Algid: ALG_ID; BaseData: HCRYPTHASH; Flags: LongWord; var Key: HCRYPTKEY): LongBool; stdcall; external _lib_ADVAPI32 name 'CryptDeriveKey';
function CryptSetKeyParam(hKey: HCRYPTKEY; dwParam: LongInt; pbData: PBYTE; dwFlags: LongInt): LongBool stdcall; stdcall; external _lib_ADVAPI32 name 'CryptSetKeyParam';
function CryptEncrypt(Key: HCRYPTKEY; Hash: HCRYPTHASH; Final: LongBool; Flags: LongWord; pbData: PBYTE; var Len: LongInt; BufLen: LongInt): LongBool;stdcall;external _lib_ADVAPI32 name 'CryptEncrypt';
function CryptDecrypt(Key: HCRYPTKEY; Hash: HCRYPTHASH; Final: LongBool; Flags: LongWord; pbData: PBYTE; var Len: LongInt): LongBool; stdcall; external _lib_ADVAPI32 name 'CryptDecrypt';
function CryptCreateHash(Prov: HCRYPTPROV; Algid: ALG_ID; Key: HCRYPTKEY; Flags: LongWord; var Hash: HCRYPTHASH): LongBool; stdcall; external _lib_ADVAPI32 name 'CryptCreateHash';
function CryptHashData(Hash: HCRYPTHASH; Data: PChar; DataLen: LongWord; Flags: LongWord): LongBool; stdcall; external _lib_ADVAPI32 name 'CryptHashData';
function CryptReleaseContext(hProv: HCRYPTPROV; dwFlags: LongWord): LongBool; stdcall; external _lib_ADVAPI32 name 'CryptReleaseContext';
function CryptDestroyHash(hHash: HCRYPTHASH): LongBool; stdcall; external _lib_ADVAPI32 name 'CryptDestroyHash';
function CryptDestroyKey(hKey: HCRYPTKEY): LongBool; stdcall; external _lib_ADVAPI32 name 'CryptDestroyKey';

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

{$WARN SYMBOL_PLATFORM OFF}

function __CryptAcquireContext(ProviderType: Integer): HCRYPTPROV;
begin
  if (not CryptAcquireContext(Result, nil, nil, ProviderType, 0)) then
  begin
    if HRESULT(GetLastError) = NTE_BAD_KEYSET then
      Win32Check(CryptAcquireContext(Result, nil, nil, ProviderType, CRYPT_NEWKEYSET))
    else
      RaiseLastOSError;
  end;
end;

function __AES128_DeriveKeyFromPassword(m_hProv: HCRYPTPROV; Password: string): HCRYPTKEY;
var
  hHash: HCRYPTHASH;
  Mode: DWORD;
begin
  Win32Check(CryptCreateHash(m_hProv, CALG_SHA_256, 0, 0, hHash));
  try
    Win32Check(CryptHashData(hHash, PChar(Password), Length(Password) * SizeOf(Char), 0));
    Win32Check(CryptDeriveKey(m_hProv, CALG_AES_128, hHash, 0, Result));
    // Wine uses a different default mode of CRYPT_MODE_EBC
    Mode := CRYPT_MODE_CBC;
    Win32Check(CryptSetKeyParam(Result, KP_MODE, Pointer(@Mode), 0));
  finally
    CryptDestroyHash(hHash);
  end;
end;

function AES128_Encrypt(Value, Password: string): string;
var
  hCProv: HCRYPTPROV;
  hKey: HCRYPTKEY;
  lul_datalen: Integer;
  lul_buflen: Integer;
  Buffer: TBytes;
begin
  Assert(Password <> '');
  if (Value = '') then
    Result := ''
  else begin
    hCProv := __CryptAcquireContext(PROV_RSA_AES);
    try
      hKey := __AES128_DeriveKeyFromPassword(hCProv, Password);
      try
        // allocate buffer space
        lul_datalen := Length(Value) * SizeOf(Char);
        Buffer := TEncoding.Unicode.GetBytes(Value + '        ');
        lul_buflen := Length(Buffer);
        // encrypt to buffer
        Win32Check(CryptEncrypt(hKey, 0, True, 0, @Buffer[0], lul_datalen, lul_buflen));
        SetLength(Buffer, lul_datalen);
        // base 64 result
        Result := Base64_Encode(Buffer);
      finally
        CryptDestroyKey(hKey);
      end;
    finally
      CryptReleaseContext(hCProv, 0);
    end;
  end;
end;

function AES128_Decrypt(Value, Password: string): string;
var
  hCProv: HCRYPTPROV;
  hKey: HCRYPTKEY;
  lul_datalen: Integer;
  Buffer: TBytes;
begin
  Assert(Password <> '');
  if Value = '' then
    Result := ''
  else begin
    hCProv := __CryptAcquireContext(PROV_RSA_AES);
    try
      hKey := __AES128_DeriveKeyFromPassword(hCProv, Password);
      try
        // decode base64
        Buffer := Base64_Decode(Value);
        // allocate buffer space
        lul_datalen := Length(Buffer);
        // decrypt buffer to to string
        Win32Check(CryptDecrypt(hKey, 0, True, 0, @Buffer[0], lul_datalen));
        Result := TEncoding.Unicode.GetString(Buffer, 0, lul_datalen);
      finally
        CryptDestroyKey(hKey);
      end;
    finally
      CryptReleaseContext(hCProv, 0);
    end;
  end;
end;

end.

sdimain.dfm

Code:

unit SDIMAIN;

interface

uses Winapi.Windows, System.Classes, Vcl.Graphics, Vcl.Forms, Vcl.Controls,
  Vcl.Menus, Vcl.Dialogs, Vcl.StdCtrls, Vcl.Buttons, Vcl.ExtCtrls, Vcl.ComCtrls,
  Vcl.ImgList, Vcl.StdActns, Vcl.ActnList, Vcl.ToolWin, System.ImageList,
  System.Actions, CryptoUtils;

type
  TSDIAppForm = class(TForm)
    txtText: TEdit;
    Label1: TLabel;
    txtCrypt: TEdit;
    Button2: TButton;
    btnEncrypt: TButton;
    Label2: TLabel;
    txtPasswort: TEdit;
    Label3: TLabel;
    procedure btnEncryptClick(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure FormCreate(Sender: TObject);
  private
    { Private-Deklarationen }
  public
    { Public-Deklarationen }
  end;

var
  SDIAppForm: TSDIAppForm;

implementation

{$R *.dfm}

procedure TSDIAppForm.btnEncryptClick(Sender: TObject);
begin
txtCrypt.Text:= AES128_Encrypt(txttext.Text,txtPasswort.text)
end;

procedure TSDIAppForm.Button2Click(Sender: TObject);
begin
txttext.text:= AES128_Decrypt(txtcrypt.Text,txtPasswort.text)
end;

procedure TSDIAppForm.FormCreate(Sender: TObject);
begin

end;

end.

gebe ich nun
in txtcrypt = asdf und txtpasswort asdf ein (wo ja nichts rauskommen kann) erhalte ich folgenden Fehler:
EOSError mit der Meldung 'Systemfehler. Code: -2146893819. Ungültige Daten'

Nutze ich den korrekten verschlüsselungsstring und das korrekte passwort , entschlüsselt er mir das auch korrekt, was mache ich falsch ?