GARbro-mirror/ArcFormats/Actgs/ArcDAT.cs

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2015-11-04 08:03:36 +08:00
//! \file ArcDAT.cs
//! \date Tue Nov 03 07:05:36 2015
//! \brief ACTGS engine resource archive.
//
// Copyright (C) 2015 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 System.Linq;
using GameRes.Utility;
using GameRes.Compression;
namespace GameRes.Formats.Actgs
{
[Serializable]
public class ActressScheme : ResourceScheme
{
public byte[][] KnownKeys;
}
internal class ActressArchive : ArcFile
{
public readonly byte[] Key;
public ActressArchive (ArcView arc, ArchiveFormat impl, ICollection<Entry> dir, byte[] key)
: base (arc, impl, dir)
{
Key = key;
}
}
[Export(typeof(ArchiveFormat))]
public class DatOpener : ArchiveFormat
{
public override string Tag { get { return "DAT/ACTGS"; } }
public override string Description { get { return "ACTGS engine resource archive"; } }
public override uint Signature { get { return 0; } }
public override bool IsHierarchic { get { return false; } }
public override bool CanCreate { get { return false; } }
public DatOpener ()
{
Extensions = new string[] { "dat" };
}
public static byte[][] KnownKeys = { };
public override ArcFile TryOpen (ArcView file)
{
int count = file.View.ReadInt32 (0);
if (!IsSaneCount (count))
return null;
if (0 != (file.View.ReadInt32 (4) | file.View.ReadInt32 (8) | file.View.ReadInt32 (12)))
return null;
const int entry_size = 0x20;
var index = new byte[count * entry_size];
if (index.Length != file.View.Read (0x10, index, 0, (uint)index.Length))
return null;
uint first_offset = 0x10u + (uint)index.Length;
uint actual_offset = LittleEndian.ToUInt32 (index, 0);
byte[] key = null;
if (actual_offset != first_offset)
{
key = FindKey (first_offset, actual_offset);
if (null == key)
return null;
Decrypt (index, 0, index.Length, key);
}
int index_offset = 0;
var dir = new List<Entry> (count);
for (int i = 0; i < count; ++i)
{
var name = Binary.GetCString (index, index_offset+8, 0x18);
if (0 == name.Length)
return null;
var entry = FormatCatalog.Instance.Create<Entry> (name);
entry.Offset = LittleEndian.ToUInt32 (index, index_offset);
entry.Size = LittleEndian.ToUInt32 (index, index_offset+4);
if (!entry.CheckPlacement (file.MaxOffset))
return null;
dir.Add (entry);
index_offset += 0x20;
}
if (null == key)
return new ArcFile (file, this, dir);
else
return new ActressArchive (file, this, dir, key);
}
public override Stream OpenEntry (ArcFile arc, Entry entry)
{
var actarc = arc as ActressArchive;
if (null == actarc || null == actarc.Key)
return base.OpenEntry (arc, entry);
if (entry.Name.EndsWith (".scr", StringComparison.InvariantCultureIgnoreCase))
{
if ('X' != arc.File.View.ReadByte (entry.Offset))
return base.OpenEntry (arc, entry);
var data = new byte[entry.Size];
arc.File.View.Read (entry.Offset, data, 0, entry.Size);
Decrypt (data, 1, data.Length-1, actarc.Key);
data[0] = (byte)'N';
return new MemoryStream (data);
}
if (arc.File.View.AsciiEqual (entry.Offset, "PAK "))
{
uint packed_size = arc.File.View.ReadUInt32 (entry.Offset+4);
var input = arc.File.CreateStream (entry.Offset+12, packed_size);
return new LzssStream (input);
}
uint length = Math.Min (entry.Size, 0x20u);
var header = new byte[length];
arc.File.View.Read (entry.Offset, header, 0, length);
Decrypt (header, 0, (int)length, actarc.Key);
if (entry.Size <= 0x20)
return new MemoryStream (header);
var rest = arc.File.CreateStream (entry.Offset+0x20, entry.Size-0x20);
return new PrefixStream (header, rest);
}
byte[] FindKey (uint first_offset, uint actual_offset)
{
var pattern = new byte[4];
LittleEndian.Pack (first_offset ^ actual_offset, pattern, 0);
return Array.Find (KnownKeys, k => k.Take (4).SequenceEqual (pattern));
}
static void Decrypt (byte[] data, int index, int length, byte[] key)
{
for (int i = 0; i < length; ++i)
{
data[index+i] ^= key[i % key.Length];
}
}
public override ResourceScheme Scheme
{
get { return new ActressScheme { KnownKeys = KnownKeys }; }
set { KnownKeys = ((ActressScheme)value).KnownKeys; }
}
}
}