aokana.php

<?php

// https://store.steampowered.com/app/1044620/

require_once 'UnityBundle.php';

chdir(__DIR__);
$f = fopen('patch.dat', 'r');
$head = fread($f, 1024);
$heads = new MemoryStream($head);
$heads->littleEndian = true;

$heads->position = 4*4;
for ($itemCount=0,$i=4;$i<255;$i++) {
  $itemCount += $heads->long;
}
$itemCount = int($itemCount);
echo "Items count: $itemCount\n";

//fseek($f, 0);
$fileInfos = fread($f, 16*$itemCount);
$heads->position = 212;
$fileInfos = dd($fileInfos, 16*$itemCount, $heads->long);
$fileInfos = array_values(unpack('V*', $fileInfos));

$firstFileOffset = $fileInfos[3];
$fileNamesLen = $firstFileOffset - (1024 + 16 * $itemCount);
$fileNames = fread($f, $fileNamesLen);
$heads->position = 92;
$fileNames = new MemoryStream(dd($fileNames, $fileNamesLen, $heads->long));
$map = [];
for ($j=0; $j<$itemCount; $j++) {
  $key = $fileNames->string;
  $map[$key] = [
    'position' => $fileInfos[4 * $j + 3],
    'length'   => $fileInfos[4 * $j + 1],
    'key'      => $fileInfos[4 * $j + 2]
  ];
}
print_r($map);

function dd($b, int $L, int $k) {
  $array = gk($k);
  for ($i=0; $i < $L; $i++) {
    $b2 = ord($b[$i]);
    $b2 ^= $array[$i%253];
    $b2 += 3;
    $b2 += $array[$i%89];
    $b2 ^= 153;
    $b[$i] = chr($b2 & 0xff);
  }
  return $b;
}
function gk(int $k0) {
  $itemCount = int($k0 * 7391 + 42828);
  $firstFileOffset = int($itemCount << 17 ^ $itemCount);
  $b = [];
  for ($i=0; $i<256; $i++) {
    $itemCount -= $k0; $itemCount = int($itemCount);
    $itemCount += $firstFileOffset; $itemCount = int($itemCount);
    $firstFileOffset = $itemCount + 56;
    $itemCount *= $firstFileOffset & 239; $itemCount = int($itemCount);
    $b[$i] = $itemCount & 0xff;
    $itemCount >>= 1; $itemCount = int($itemCount);
  }
  return $b;
}
function int(int $d) {return $d&0xffffffff;}