GARbro-mirror/ArcFormats/Unity/ArcBIN.cs

248 lines
8.7 KiB
C#
Raw Normal View History

2019-02-25 17:04:47 +08:00
//! \file ArcBIN.cs
//! \date 2019 Feb 23
//! \brief Unity binary data asset.
//
// 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;
using System.Collections.Generic;
using System.ComponentModel.Composition;
using System.IO;
using System.Linq;
using System.Security.Cryptography;
using System.Text;
using GameRes.Utility;
namespace GameRes.Formats.Unity
{
internal class BinArchive : ArcFile
{
public readonly Aes Encryption;
public BinArchive (ArcView arc, ArchiveFormat impl, ICollection<Entry> dir, Aes enc)
: base (arc, impl, dir)
{
Encryption = enc;
}
#region IDisposable Members
bool _bin_disposed = false;
protected override void Dispose (bool disposing)
{
if (_bin_disposed)
return;
if (disposing)
Encryption.Dispose();
_bin_disposed = true;
base.Dispose (disposing);
}
#endregion
}
[Serializable]
public class BinPackKey
{
public byte[] Key;
public byte[] IV;
public BinPackKey (string key, string iv)
{
Key = Encoding.UTF8.GetBytes (key);
IV = Encoding.UTF8.GetBytes (iv);
}
}
[Serializable]
public class BinPackScheme : ResourceScheme
{
public Dictionary<string, BinPackKey> KnownKeys;
}
[Export(typeof(ArchiveFormat))]
public class BinOpener : ArchiveFormat
{
public override string Tag { get { return "BIN/IDX"; } }
public override string Description { get { return "Unity engine resource asset"; } }
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)
{
if (!file.Name.HasExtension (".bin"))
return null;
var idx_name = Path.ChangeExtension (file.Name, "idx");
if (!VFS.FileExists (idx_name))
return null;
var scheme = QueryScheme (file.Name);
if (null == scheme)
return null;
var dir = new List<Entry>();
using (var idx = VFS.OpenBinaryStream (idx_name))
using (var aes = Aes.Create())
{
aes.Padding = PaddingMode.PKCS7;
aes.Mode = CipherMode.CBC;
aes.KeySize = 128;
aes.Key = scheme.Key;
aes.IV = scheme.IV;
var input_buffer = new byte[0x100];
var unpacker = new BinDeserializer();
while (idx.PeekByte() != -1)
{
int length = idx.ReadInt32();
if (length <= 0)
return null;
if (length > input_buffer.Length)
input_buffer = new byte[length];
if (idx.Read (input_buffer, 0, length) < length)
return null;
using (var decryptor = aes.CreateDecryptor())
using (var encrypted = new MemoryStream (input_buffer, 0, length))
using (var input = new InputCryptoStream (encrypted, decryptor))
{
var info = unpacker.DeserializeEntry (input);
var filename = info["fileName"] as string;
if (string.IsNullOrEmpty (filename))
return null;
filename = filename.TrimStart ('/', '\\');
var entry = Create<Entry> (filename);
entry.Offset = Convert.ToInt64 (info["index"]);
entry.Size = Convert.ToUInt32 (info["size"]);
if (!entry.CheckPlacement (file.MaxOffset))
return null;
dir.Add (entry);
}
}
}
if (0 == dir.Count)
return null;
var arc_aes = Aes.Create();
arc_aes.Padding = PaddingMode.PKCS7;
arc_aes.Mode = CipherMode.CBC;
arc_aes.KeySize = 256;
arc_aes.Key = scheme.Key;
arc_aes.IV = scheme.IV;
return new BinArchive (file, this, dir, arc_aes);
}
public override Stream OpenEntry (ArcFile arc, Entry entry)
{
var bin_arc = (BinArchive)arc;
var decryptor = bin_arc.Encryption.CreateDecryptor();
var input = arc.File.CreateStream (entry.Offset, entry.Size);
return new InputCryptoStream (input, decryptor);
}
BinPackKey QueryScheme (string arc_name)
{
return DefaultScheme.KnownKeys.Values.FirstOrDefault();
}
static BinPackScheme DefaultScheme = new BinPackScheme { KnownKeys = new Dictionary<string, BinPackKey>() };
public override ResourceScheme Scheme
{
get { return DefaultScheme; }
set { DefaultScheme = (BinPackScheme)value; }
}
}
internal class BinDeserializer
{
byte[] m_buffer = new byte[0x20];
public IDictionary DeserializeEntry (Stream input)
{
int id = input.ReadByte();
if (id < 0x80 || id > 0x8F)
throw new FormatException();
int field_count = id & 0xF;
var map = new Hashtable (field_count);
for (int i = 0; i < field_count; ++i)
{
id = input.ReadByte();
if (id < 0xA0 || id > 0xBF)
throw new FormatException();
int length = id & 0x1F;
if (input.Read (m_buffer, 0, length) < length)
throw new FormatException();
var key = Encoding.UTF8.GetString (m_buffer, 0, length);
var value = ReadField (input);
map[key] = value;
}
return map;
}
object ReadField (Stream input)
{
int id = input.ReadByte();
if (id >= 0 && id < 0x80)
{
return id;
}
else if (id >= 0xA0 && id < 0xC0)
{
int length = id & 0x1F;
return ReadString (input, length);
}
switch (id)
{
case 0xD0: // Int8
int value = input.ReadByte();
if (-1 == value)
throw new FormatException();
return (sbyte)value;
case 0xD1: // Int16
if (input.Read (m_buffer, 0, 2) < 2)
throw new FormatException();
return BigEndian.ToInt16 (m_buffer, 0);
case 0xD2: // Int32
if (input.Read (m_buffer, 0, 4) < 4)
throw new FormatException();
return BigEndian.ToInt32 (m_buffer, 0);
case 0xDA: // Raw16
if (input.Read (m_buffer, 0, 2) < 2)
throw new FormatException();
int length = BigEndian.ToUInt16 (m_buffer, 0);
return ReadString (input, length);
default:
throw new FormatException();
}
}
string ReadString (Stream input, int length)
{
if (length > m_buffer.Length)
m_buffer = new byte[(length + 0xF) & ~0xF];
input.Read (m_buffer, 0, length);
return Encoding.UTF8.GetString (m_buffer, 0, length);
}
}
}