GARbro-mirror/Legacy/Saiki/ImageJPX.cs

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2017-12-08 18:45:45 +08:00
//! \file ImageJPX.cs
//! \date 2017 Dec 06
//! \brief Obfuscated images.
//
// Copyright (C) 2017 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.ComponentModel.Composition;
using System.IO;
using GameRes.Utility;
namespace GameRes.Formats.Saiki
{
public abstract class ObfuscatedImageFormat : ImageFormat
{
const int DefaultEncryptedLength = 200;
internal static IBinaryStream OpenEncrypted (IBinaryStream input, int encrypted_length = DefaultEncryptedLength)
{
input.Position = 0;
var header = input.ReadBytes (encrypted_length+2);
header[0] ^= 0xFF;
header[1] = Binary.RotByteL ((byte)~header[1] , 1);
int shift = 1;
byte count = header[0];
for (int i = 2; i < header.Length; ++i)
{
header[i] = Binary.RotByteL (header[i], shift);
if (++shift >= 7)
shift = 1;
if (--count == 0)
{
if (shift <= 4)
count = header[1];
else
count = header[0];
shift = 1;
}
}
Stream stream = new StreamRegion (input.AsStream, header.Length, true);
stream = new PrefixStream (header, stream);
return new BinaryStream (stream, input.Name);
}
}
[Export(typeof(ImageFormat))]
public class JpxFormat : ObfuscatedImageFormat
{
public override string Tag { get { return "JPX"; } }
public override string Description { get { return "Obfuscated JPEG image"; } }
public override uint Signature { get { return 0; } }
public override bool CanWrite { get { return false; } }
public JpxFormat ()
{
Signatures = new uint[] { 0x38FF9300, 0 };
}
public override ImageMetaData ReadMetaData (IBinaryStream stream)
{
var header = stream.ReadHeader (2);
if (header[0] != 0 || header[1] != 0x93)
return null;
using (var jpg = OpenEncrypted (stream))
return Jpeg.ReadMetaData (jpg);
}
public override ImageData Read (IBinaryStream stream, ImageMetaData info)
{
using (var jpg = OpenEncrypted (stream))
return Jpeg.Read (jpg, info);
}
public override void Write (Stream file, ImageData image)
{
throw new System.NotImplementedException ("JpxFormat.Write not implemented");
}
}
[Export(typeof(ImageFormat))]
public class BmxFormat : ObfuscatedImageFormat
{
public override string Tag { get { return "BMX"; } }
public override string Description { get { return "Obfuscated BMP image"; } }
public override uint Signature { get { return 0; } }
public override bool CanWrite { get { return false; } }
public override ImageMetaData ReadMetaData (IBinaryStream stream)
{
var header = stream.ReadHeader (2);
if (header[0] != 0xBD || header[1] != 0x59)
return null;
using (var bmp = OpenEncrypted (stream))
return Bmp.ReadMetaData (bmp);
}
public override ImageData Read (IBinaryStream stream, ImageMetaData info)
{
using (var bmp = OpenEncrypted (stream))
return Bmp.Read (bmp, info);
}
public override void Write (Stream file, ImageData image)
{
throw new System.NotImplementedException ("BmxFormat.Write not implemented");
}
}
}