program NitradoEnc;

{$APPTYPE CONSOLE}

uses
  SysUtils,
  Classes,
  zlib,
  Math,
  AnsiStrings,
  StrUtils;

var
  ms1, ms2: TMemoryStream;
  z: TZCompressionStream;
  i, j: Integer;
  b, count: Byte;
  size: Integer;
  temp: Cardinal;

const
  Vigenère: AnsiString = '2lly4t4SI8cHoU4h.rk90bk/CvYUq8c4Ols1STx';
  Base64: AnsiString = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/';

begin
  try
    writeln('Nitrado-Snapshot-Enkoder v1.1 // yat.qa // 10. Dezember 2016');
    ms1 := TMemoryStream.Create;
    ms2 := TMemoryStream.Create;
    ms1.LoadFromFile(paramstr(1));
    // Absätze am Ende erkennen
    Size := ms1.Size;
    repeat
      dec(Size);
      ms1.Position := Size;
      ms1.ReadBuffer(b, 1);
    until (b <> $0a) and (b <> $0d);
    inc(size);
    writeln(ms1.Size - Size, ' Bytes am Ende entfernt');
    ms1.Position := 0;
    // BOM erkennen
    ms1.ReadBuffer(b, 1);
    if b = $ef then
    ms1.ReadBuffer(temp, 2)
    else
    ms1.Position := 0;
    // Vigenère-Encoder
    for i := 0 to Size - ms1.Position - 1 do
    begin
      ms1.ReadBuffer(b, 1);
      b := b + Byte(Vigenère[i mod 39 + 1]);
      ms2.WriteBuffer(b, 1);
    end;
    ms1.Clear;
    ms2.Position := 0;
    //ms2.SaveToFile(paramstr(1) + '.enc');
    // Base64-Encoder (binary-safe)
    Size := ms2.Size;
    Count := 3; // Compiler-Blabla
    for i := 0 to (Size + 2) div 3 - 1 do
    begin
      count := Min(Size - i * 3, 3);
      ms2.ReadBuffer(temp, Count);
      temp := temp and $ff00 + temp shl 16 + (temp shr 16) and $ff; // Endianness drehen (vereinfacht weil nur 3 Byte verwendet)
      for j := 0 to Count do
      begin
        b := Byte(Base64[(temp shr 18) and $3f + 1]);
        temp := temp shl 6;
        ms1.WriteBuffer(b, 1);
      end;
      if (i + 1) mod 15 = 0 then
      begin
        b := $0A;
        ms1.WriteBuffer(b, 1);
      end;
    end;
    b := $3D;
    for j := Count to 2 do
    ms1.WriteBuffer(b, 1);
    b := $0A;
    ms1.WriteBuffer(b, 1);
    // zlib-Komprimierung
    ms2.Clear;
    ms1.Position := 0;
    z := TCompressionStream.Create(ms2);
    z.CopyFrom(ms1, ms1.Size);
    z.Free; // geht sonst manchmal nicht
    ms2.SaveToFile(paramstr(1) + '.zlib');
    writeln('Erfolgreich kodiert!');
  except
    on E:Exception do
      Writeln(E.Classname, ': ', E.Message);
  end;
  readln;
end.