GARbro-mirror/ArcFormats/Cmvs/ArcPBZ.cs

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//! \file ArcPBZ.cs
//! \date Thu Jun 23 19:12:32 2016
//! \brief PVNS engine (CMVS precursor) resource archive.
//
// Copyright (C) 2016 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;
namespace GameRes.Formats.Pvns
{
internal class PbzArchive : ArcFile
{
public readonly byte[] ArcKey;
public readonly byte[] ScriptKey;
public PbzArchive (ArcView arc, ArchiveFormat impl, ICollection<Entry> dir, PbzKeys scheme)
: base (arc, impl, dir)
{
ArcKey = scheme.ArcKey;
ScriptKey = scheme.ScriptKey;
}
}
[Serializable]
public class PbzKeys
{
public byte[] ArcKey;
public byte[] ScriptKey;
}
[Serializable]
public class PbzScheme : ResourceScheme
{
public Dictionary<string, PbzKeys> KnownSchemes;
}
[Export(typeof(ArchiveFormat))]
public class PbzOpener : ArchiveFormat
{
public override string Tag { get { return "PBZ"; } }
public override string Description { get { return "PVNS engine resource archive"; } }
public override uint Signature { get { return 0x315A4250; } } // 'PBZ1'
public override bool IsHierarchic { get { return false; } }
public override bool CanWrite { get { return false; } }
public static Dictionary<string, PbzKeys> KnownSchemes = new Dictionary<string, PbzKeys>();
public override ResourceScheme Scheme
{
get { return new PbzScheme { KnownSchemes = KnownSchemes }; }
set { KnownSchemes = ((PbzScheme)value).KnownSchemes; }
}
public override ArcFile TryOpen (ArcView file)
{
if (0 == KnownSchemes.Count)
return null;
int count = file.View.ReadInt32 (4);
if (!IsSaneCount (count))
return null;
uint index_size = file.View.ReadUInt32 (8);
var index = file.View.ReadBytes (0x10, index_size);
if (index.Length != index_size)
return null;
var scheme = KnownSchemes.Values.First(); // XXX
Decrypt (index, scheme.ArcKey);
long base_offset = 0x10 + index_size;
int index_pos = 0;
var dir = new List<Entry> (count);
for (int i = 0; i < count; ++i)
{
int entry_size = LittleEndian.ToInt32 (index, index_pos);
if (entry_size <= 0x18)
return null;
var name = Binary.GetCString (index, index_pos+0x18, entry_size - 0x18);
var entry = FormatCatalog.Instance.Create<Entry> (name);
entry.Size = LittleEndian.ToUInt32 (index, index_pos+4);
entry.Offset = base_offset + LittleEndian.ToUInt32 (index, index_pos+8);
if (!entry.CheckPlacement (file.MaxOffset))
return null;
dir.Add (entry);
index_pos += entry_size;
}
return new PbzArchive (file, this, dir, scheme);
}
public override Stream OpenEntry (ArcFile arc, Entry entry)
{
var parc = arc as PbzArchive;
if (null == parc)
return base.OpenEntry (arc, entry);
var data = arc.File.View.ReadBytes (entry.Offset, entry.Size);
Decrypt (data, parc.ArcKey);
if (entry.Name.EndsWith (".scr", StringComparison.InvariantCultureIgnoreCase)
&& Binary.AsciiEqual (data, "PSRA") && data.Length > 20)
{
data = DecryptScript (data, parc.ScriptKey);
}
return new MemoryStream (data);
}
static void Decrypt (byte[] data, byte[] key)
{
if (0 == key.Length)
return;
for (int i = 0; i < data.Length; ++i)
{
data[i] = (byte)((data[i] ^ key[i % key.Length]) + 0x80);
}
}
byte[] DecryptScript (byte[] data, byte[] key)
{
int input_size = data.Length - 0x14;
for (int i = 4; i < 0x14; ++i)
{
data[i] = (byte)((data[i] ^ 0xF5) - 0x10);
}
if (0 != (input_size & -4))
{
unsafe
{
fixed (byte* data8 = &data[0x14])
{
uint m = 0x817543;
uint* data32 = (uint*)data8;
for (int length = (((input_size & -4) - 1) >> 2) + 1; length > 0; --length)
{
*data32 ^= m;
m += 0x1352467u;
++data32;
}
}
}
}
uint checksum = LittleEndian.ToUInt32 (data, 4);
for (int i = 0x14; i < data.Length; ++i)
{
checksum -= data[i];
}
if (checksum != 0)
throw new InvalidEncryptionScheme();
for (int i = 0x14; i < data.Length; ++i)
{
data[i] = Binary.RotByteR (data[i], 3);
}
int src = 0x14;
for (int count = ((input_size - 2) >> 1) + 1; count > 0; --count)
{
byte t = data[src];
data[src] = data[src+1];
data[src+1] = t;
src += 2;
}
int k = 0;
for (int i = 0x14; i < data.Length; ++i)
{
data[i] = (byte)((data[i] ^ key[k++]) + 0x35);
k %= key.Length;
}
int unpacked_size = LittleEndian.ToInt32 (data, 0x10);
var output = new byte[unpacked_size];
src = 0x14 + LittleEndian.ToInt32 (data, 8);
int dst = 0;
int bit_mask = 0x80;
int bits = 0x14;
while (dst < output.Length)
{
if (0 == bit_mask)
{
bit_mask = 0x80;
++bits;
}
if (0 != (bit_mask & data[bits]))
{
int u = LittleEndian.ToUInt16 (data, src);
src += 2;
int offset = (u >> 5) + 1;
int count = (u & 0x1F) + 3;
Binary.CopyOverlapped (output, dst - offset, dst, count);
dst += count;
}
else
{
output[dst++] = data[src++];
}
bit_mask >>= 1;
}
for (int i = 0; i < output.Length; ++i)
{
output[i] ^= 0x7E;
}
return output;
}
}
}