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2018-01-09 04:30:43 +04:00
//! \file ArcCG.cs
//! \date 2018 Jan 09
//! \brief ACTGS engine encrypted archive.
//
// Copyright (C) 2018 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.Linq;
namespace GameRes.Formats.Actgs
{
[Export(typeof(ArchiveFormat))]
public class CgOpener : DatOpener
{
public override string Tag { get { return "CG/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 CanWrite { get { return false; } }
public override ArcFile TryOpen (ArcView file)
{
var key = FindKey (file);
if (null == key)
return null;
uint signature_key = key.ToUInt32 (0);
int count = (int)(file.View.ReadUInt32 (0) ^ signature_key);
if (!IsSaneCount (count))
return null;
uint index_size = 32 * (uint)count;
using (var enc = file.CreateStream (0x10, index_size))
using (var input = new ByteStringEncryptedStream (enc, key))
using (var index = new BinaryStream (input, file.Name))
{
var reader = new IndexReader (file.MaxOffset);
var dir = reader.Read (index, count);
if (null == dir)
return null;
return new ActressArchive (file, this, dir, key);
}
}
byte[] FindKey (ArcView file)
{
var pattern = file.View.ReadBytes (4, 8);
return Array.Find (KnownKeys, k => KeySequence (k).Skip (4).Take (8).SequenceEqual (pattern));
}
internal static IEnumerable<byte> KeySequence (byte[] key)
{
for (;;)
{
for (int i = 0; i < key.Length; ++i)
yield return key[i];
}
}
}
}