GARbro-mirror/ArcFormats/Unity/PMaster/ArcDAT.cs

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2019-03-04 08:01:53 +08:00
//! \file ArcDAT.cs
//! \date 2019 Feb 26
//! \brief Unity PMaster engine resource archive.
//
// Copyright (C) 2019 by morkt
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to
// deal in the Software without restriction, including without limitation the
// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
// sell copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
// IN THE SOFTWARE.
//
using System;
using System.Collections.Generic;
using System.ComponentModel.Composition;
using System.IO;
using GameRes.Utility;
namespace GameRes.Formats.Unity.PMaster
{
internal class PMasterEntry : Entry
{
public uint Key;
}
[Export(typeof(ArchiveFormat))]
public class DatOpener : ArchiveFormat
{
public override string Tag { get { return "DAT/PMASTER"; } }
public override string Description { get { return "Unity PMaster engine resource archive"; } }
public override uint Signature { get { return 0; } }
public override bool IsHierarchic { get { return true; } }
public override bool CanWrite { get { return false; } }
public override ArcFile TryOpen (ArcView file)
{
int count = 0;
for (int i = 0; i < 0x400; i += 4)
count += file.View.ReadInt32 (i);
if (!IsSaneCount (count))
return null;
uint index_length = (uint)count * 0x10;
if (index_length >= file.MaxOffset)
return null;
var index = file.View.ReadBytes (0x400, index_length);
DecryptData (index, file.View.ReadUInt32 (0xD4));
uint first_offset = index.ToUInt32 (4);
if (first_offset >= file.MaxOffset || first_offset <= (0x400 + index_length))
return null;
uint names_length = first_offset - (0x400 + index_length);
var names = file.View.ReadBytes (0x400 + index_length, names_length);
DecryptData (names, file.View.ReadUInt32 (0x5C));
int index_pos = 0;
var dir = new List<Entry> (count);
for (int i = 0; i < count; ++i)
{
int name_pos = index.ToInt32 (index_pos);
var name = Binary.GetCString (names, name_pos);
var entry = Create<PMasterEntry> (name);
entry.Offset = index.ToUInt32 (index_pos+4);
entry.Size = index.ToUInt32 (index_pos+8);
entry.Key = index.ToUInt32 (index_pos+12);
if (!entry.CheckPlacement (file.MaxOffset))
return null;
dir.Add (entry);
index_pos += 16;
}
return new ArcFile (file, this, dir);
}
public override Stream OpenEntry (ArcFile arc, Entry entry)
{
var pent = (PMasterEntry)entry;
var data = arc.File.View.ReadBytes (entry.Offset, entry.Size);
DecryptData (data, pent.Key);
return new BinMemoryStream (data, entry.Name);
}
void DecryptData (byte[] data, uint seed)
{
var key = GenerateKey (seed);
for (int i = 0; i < data.Length; i++)
{
byte b = data[i];
b ^= key[i & 0xFF];
b += 0x4D;
b += key[i % 0x2B];
b -= key[i & 0xFF];
b ^= 0x23;
data[i] = b;
}
}
byte[] GenerateKey (uint seed)
{
var key = new byte[256];
uint n = seed * 2281 + 59455;
uint n2 = (n << 17) ^ n;
for (int i = 0; i < 256; i++)
{
n >>= 5;
n ^= n2;
n *= 471;
n -= seed;
n += n2;
n2 = n + 87;
n ^= n2 & 91;
key[i] = (byte)n;
n >>= 1;
}
return key;
}
}
}