RANDOM ENCODE BY SKTHELIGHT

unit unit1;

{$mode objfpc}{$H+}

interface

uses
  Classes, SysUtils, FileUtil, Forms, Controls, Graphics, Dialogs, StdCtrls,
  base64;
const
     cae='ABCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz0123456789!#$%&()[<=?@]^_|0123456789!#$%&()[<=?@]^_|' ;
type

  { TForm1 }

  TForm1 = class(TForm)
    Button1: TButton;
    Button2: TButton;
    Edit1: TEdit;
    Edit2: TEdit;
    Edit3: TEdit;
    Label1: TLabel;
    Label2: TLabel;
    Label3: TLabel;
    Label4: TLabel;
    Label5: TLabel;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
  private
    { private declarations }
  public
    { public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.lfm}

{ TForm1 }
function ranEncode(x,flag:ansistring;Private_key:byte):ansistring;//Flag_STring
Var
   temp:ansistring;
   i,j:longint;
   k:byte;
begin
     temp:='';
     x:=encodeStringBase64(x);
     for i:=length(x) downto 1 do
         temp:=temp+x[i];
     for i:=1 to Private_key do
         begin
              temp:=flag+temp;
              k:=random(25)+1;
              for j:=1 to length(temp) do
                  begin
                       temp[j]:=cae[pos(temp[j],cae)+k];
                  end;
         end;
     x:='';
     for i:=length(temp) downto 1 do
         x:=x+temp[i];
     temp:='';
     ranencode:=x;
end;
function ranDecode(x,FLAG:ansistring;Private_key:byte):ansistring;
var
   st,temp:ansistring;
   i,j:longint;
   k:byte;
begin
     temp:='';
     for i:=length(x) downto 1 do
         temp:=temp+x[i];
     x:=temp;
     temp:='';
     for i:=1 to Private_key do
         begin
         for k:=1 to 25 do
                       begin
                            temp:=x;
                            for j:=1 to length(temp) do
                            temp[j]:=cae[pos(temp[j],cae)+k];
                            st:=copy(temp,1,length(FLAG));
                            if st=FLAG then begin x:=copy(temp,length(FLAG)+1,length(temp)-length(FLAG));break; end;
                       end;
         end;
     temp:='';
     for i:=length(x) downto 1 do
         temp:=temp+x[i];
     randecode:=decodeStringBase64(temp);
end;


procedure TForm1.Button1Click(Sender: TObject);
begin
      edit2.text:=ranencode(edit1.text,'FLAG',20);
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
     edit3.text:=randecode(edit2.text,'FLAG',20);
end;

end.