Fórum criptografia de dados no delphi #346224

function TForm1.Cripto(Action, Src, Key: WideString): WideString;
var
   KeyLen    : Integer;
   KeyPos    : Integer;
   offset    : Integer;
   dest      : string;
   SrcPos    : Integer;
   SrcAsc    : Integer;
   TmpSrcAsc : Integer;
   Range     : Integer;
    s : string[255];
    c : array[0..255] of Byte absolute s;
    i: Integer;
begin
     dest:=´´;
     KeyLen:=Length(Key);
     KeyPos:=0;
     SrcPos:=0;
     SrcAsc:=0;
     Range:=256;
     if Action = UpperCase(´E´) then
     begin
          Randomize;
          offset:=Random(Range);
          dest:=format(´¬1.2x´,[offset]);
          for SrcPos := 1 to Length(Src) do
          begin
               SrcAsc:=(Ord(Src[SrcPos]) + offset) MOD 255;
               if KeyPos < KeyLen then KeyPos:= KeyPos + 1 else KeyPos:=1;
               SrcAsc:= SrcAsc xor Ord(Key[KeyPos]);
               dest:=dest + format(´¬1.2x´,[SrcAsc]);
               offset:=SrcAsc;
          end;
     end;
     if Action = UpperCase(´D´) then
     begin
          offset:=StrToInt(´$´+ copy(src,1,2));
          SrcPos:=3;
          repeat
                SrcAsc:=StrToInt(´$´+ copy(src,SrcPos,2));
                if KeyPos < KeyLen Then KeyPos := KeyPos + 1 else KeyPos := 1;
                TmpSrcAsc := SrcAsc xor Ord(Key[KeyPos]);
                if TmpSrcAsc <= offset then
                     TmpSrcAsc := 255 + TmpSrcAsc - offset
                else
                     TmpSrcAsc := TmpSrcAsc - offset;
                dest := dest + chr(TmpSrcAsc);
                offset:=srcAsc;
                SrcPos:=SrcPos + 2;
          until SrcPos >= Length(Src);
     end;
     Cripto:=dest;
end;

ShowMessage(Cripto(´E´,´VALOR PARA CRIPTOGRAFIA´,´CHAVE´))

ShowMessage(Cripto(´D´,´VALOR PARA DESCRIPTOGRAFIA´,´CHAVE´))