SIFAS.php

<?php
// https://github.com/esterTion/unity-texture-toolkit/blob/master/UnityBundle.php
require_once 'UnityBundle.php';

// master data manifest
$f = new FileStream('masterdata_i_ja');
$f->littleEndian = true;

// head sha1? skipped in code
$f->position = 20;

function ReadByte(Stream $f) {
  return hexdec(bin2hex($f->byte));
}
function ReadInt(Stream $f) {
  $val = ReadByte($f);
  if ($val >= 128) {
    $b2 = ReadByte($f);
    $b3 = ReadByte($f);
    $b4 = ReadByte($f);
    $val = $val + (($b2 + (($b3 + ($b4 << 8)) << 8)) << 7);
  }
  return $val;
}
function ReadString(Stream $f) {
  $strlen = ReadInt($f);
  return $f->readData($strlen);
}
function GetKeyData($k) {
  $keys = [];
  for ($i=0; $i<strlen($k); $i+=8) {
    $keys[] = hexdec(substr($k, $i, 8));
  }
  return $keys;
}

// three header things
$hash = ReadString($f);
$lang = ReadString($f);
$rows = ReadInt($f);

$out = [];
for ($i=0; $i < $rows; $i++) {
  $v15 = ReadString($f); // db name
  $v16 = ReadString($f); // db keys
  $out[] = [$v15, $v16, GetKeyData($v16)];
}
for ($i=0; $i < $rows; $i++) {
  $out[$i][] = bin2hex($f->readData(20)); // download sha1 hash
  $out[$i][] = ReadInt($f); // download file size
}

//print_r($out[0]);

// find at Namespace: LLAS.DM.Dbapi Constant, SqliteKey1 & 2 & 3
$constKeys = [
  0x3039, // 12345
  0x10932,// 67890
  0x7AB7  // 31415
];
for ($i=0; $i<count($out); $i++) {
  $keys = [
    $constKeys[0] ^ $out[$i][2][0],
    $constKeys[1] ^ $out[$i][2][1],
    $constKeys[2] ^ $out[$i][2][2],
  ];
  if (!file_exists($out[$i][0])) continue;
  print_r($out[$i]);
  $data = (file_get_contents($out[$i][0]));

  $data = SIFAS_Decrypt_Stream($data, ...$keys);
  file_put_contents($out[$i][0].'-dec.db.gz', $data);
  file_put_contents($out[$i][0].'-dec.db', gzinflate($data));
}

function SIFAS_Decrypt_Stream(string $data, int $key0, int $key1, int $key2) {
  for ($j=0; $j<strlen($data); $j++) {
    $data[$j] = $data[$j] ^ chr((($key1 ^ $key0 ^ $key2) >> 24) & 0xff);
    $key0 = (0x343fd * $key0 + 0x269ec3) & 0xFFFFFFFF;
    $key1 = (0x343fd * $key1 + 0x269ec3) & 0xFFFFFFFF;
    $key2 = (0x343fd * $key2 + 0x269ec3) & 0xFFFFFFFF;
  }
  return $data;
}

/*
Read assets: (not tested)
SIFAS_Decrypt_Stream($encrypted_asset_data, 12345, $key1, $key2)
$key1 & $key2 from asset_i_ja_0.db
*/