Funktion von altem DEC in neues DEC 6.3

[EdAdvokat]

Hallo,
anbei die unit tools.crypt, die auch mit DEC 6.3 laufen sollte. Ich habe sie in einem kleinen
Projekt "KeyGenerator" mit DEC 6.41 verarbeitet, um eine Memo-Liste zu verschlüsseln und dann
wahlweise auch wieder zu entschlüsseln.
Dazu greife ich auf ein edit-Feld mit dem Key zu, der natürlich nur als ##### zu erkennen ist.
Natürlich könnten div. units aus diesem Tool herausgenommen werden, da du diese nicht benötigst.
Ist es das was du suchts?

Delphi-Quellcode:

unit Tools.Crypt;

interface

uses
  System.SysUtils,
  DECUtil, DECHash,
  //DECCipher, DECFmt;
  DECHashBase, DECCipherBase, DECCiphers, DECFormatBase, DECFormat,
  DECHashAuthentication, DECRandom;

const
  conKey = 'aYr14iaz8u)xO7Ok';

var
  CipherMode: TCipherMode = cmCBCx;
  HashClass: TDECHashClass = THash_SHA256;
  TextFormat: TDECFormatClass = TFormat_Base64;
  KDFIndex: LongWord = 1;

type
  TToolsCrypt = class
  public
    class function Decrypt(aHash: string; aKey: string = ''): string;
    class function Encrypt(aText: string; aKey: string = ''): string;
  end;

implementation

{ TToolsCrypt }

class function TToolsCrypt.Decrypt(aHash, aKey: string): string;
var
  Cipher: TCipher_Rijndael;
  Salt: RawByteString; //Binary;
  Data: RawByteString;
  Check: RawByteString;
  Pass: RawByteString;
  PassBytes: TBytes;
  Len: Integer;
begin
  if aKey = '' then
  begin
    aKey := conKey;
  end;

  HashClass:=TDECHashClass(THash_SHA256.create);

 try
  Cipher := TCipher_Rijndael.Create;
  try
    Salt := ValidFormat(TextFormat).Decode(RawByteString(aHash));
    Len := Length(Salt) - 16 - Cipher.Context.BufferSize;
    Data := Copy(Salt, 17, Len);
    Check := Copy(Salt, Len + 17, Cipher.Context.BufferSize);
    SetLength(Salt, 16);
    PassBytes := THash_SHA256.KDFx(aKey[1],
                                  Length(aKey) * 2,
                                  Salt[1],
                                  Length(Salt),
                                  Cipher.Context.KeySize,
                                  KDFIndex);

    SetLength(Pass, Length(PassBytes));
    Move(PassBytes[0], Pass[low(Pass)], Length(PassBytes));

    Cipher.Mode := CipherMode;
    Cipher.Init(Pass);
    SetLength(Result, Len div 2);
    Cipher.Decode(Data[1], Result[1], Len);
    if Check <> Cipher.CalcMAC then
    begin
      Result := '';
    end;
  finally
    Cipher.Free;
    //ProtectBinary(Salt);
    ProtectString(Salt);
    ProtectString(Data);
    ProtectString(Check);
    ProtectString(Pass);
  end;

 finally
   THash_SHA256(HashClass).Free;
 end;

end;

class function TToolsCrypt.Encrypt(aText, aKey: string): string;
var
  Cipher: TCipher_Rijndael;
  SaltBytes : TBytes;
  Salt: RawByteString; //Binary;
  Data: RawByteString; //Binary;
  Pass: RawByteString; //Binary;
  PassBytes: TBytes;
begin
  if aKey = '' then
  begin
    aKey := conKey;
  end;

  HashClass:=TDECHashClass(THash_SHA256.create);
 try

  Cipher := TCipher_Rijndael.Create;
  try
    SaltBytes := RandomBytes(16); //RandomBinary(16);
    SetLength(Salt, Length(SaltBytes));
    Move(SaltBytes[0], Salt[low(Salt)], Length(SaltBytes));

    PassBytes := THash_SHA256.KDFx(aKey[1],
                                  Length(aKey) * 2,
                                  Salt[1],
                                  Length(Salt),
                                  Cipher.Context.KeySize,
                                  KDFIndex);

    SetLength(Pass, Length(PassBytes));
    Move(PassBytes[0], Pass[low(Pass)], Length(PassBytes));

    Cipher.Mode := CipherMode;
    Cipher.Init(Pass);
    SetLength(Data, Length(aText) * 2);
    Cipher.Encode(aText[1], Data[1], Length(Data));
    Result := string(ValidFormat(TextFormat).Encode(Salt + Data + Cipher.CalcMAC));
  finally
    Cipher.Free;
    ProtectString(Salt);
    ProtectString(Data);
    ProtectString(Pass);
  end;
 finally
   THash_SHA256(HashClass).Free;
 end;
end;

end.