Files
OpenRA/OpenRA.FileFormats/Package.cs
2010-07-18 16:48:21 +12:00

155 lines
3.7 KiB
C#

#region Copyright & License Information
/*
* Copyright 2007-2010 The OpenRA Developers (see AUTHORS)
* This file is part of OpenRA, which is free software. It is made
* available to you under the terms of the GNU General Public License
* as published by the Free Software Foundation. For more information,
* see LICENSE.
*/
#endregion
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
namespace OpenRA.FileFormats
{
public interface IFolder
{
Stream GetContent(string filename);
IEnumerable<uint> AllFileHashes();
}
public class Package : IFolder
{
readonly Dictionary<uint, PackageEntry> index;
readonly bool isRmix, isEncrypted;
readonly long dataStart;
readonly Stream s;
public Package(string filename)
{
s = FileSystem.Open(filename);
BinaryReader reader = new BinaryReader(s);
uint signature = reader.ReadUInt32();
isRmix = 0 == (signature & ~(uint)(MixFileFlags.Checksum | MixFileFlags.Encrypted));
if (isRmix)
{
isEncrypted = 0 != (signature & (uint)MixFileFlags.Encrypted);
if( isEncrypted )
{
index = ParseRaHeader( s, out dataStart ).ToDictionary(x => x.Hash);
return;
}
}
else
s.Seek( 0, SeekOrigin.Begin );
isEncrypted = false;
index = ParseTdHeader(s, out dataStart).ToDictionary(x => x.Hash);
}
const long headerStart = 84;
List<PackageEntry> ParseRaHeader(Stream s, out long dataStart)
{
BinaryReader reader = new BinaryReader(s);
byte[] keyblock = reader.ReadBytes(80);
byte[] blowfishKey = new BlowfishKeyProvider().DecryptKey(keyblock);
uint[] h = ReadUints(reader, 2);
Blowfish fish = new Blowfish(blowfishKey);
MemoryStream ms = Decrypt( h, fish );
BinaryReader reader2 = new BinaryReader(ms);
ushort numFiles = reader2.ReadUInt16();
uint datasize = reader2.ReadUInt32();
s.Position = headerStart;
reader = new BinaryReader(s);
int byteCount = 6 + numFiles * PackageEntry.Size;
h = ReadUints( reader, ( byteCount + 3 ) / 4 );
ms = Decrypt( h, fish );
dataStart = headerStart + byteCount + ( ( ~byteCount + 1 ) & 7 );
long ds;
return ParseTdHeader( ms, out ds );
}
static MemoryStream Decrypt( uint[] h, Blowfish fish )
{
uint[] decrypted = fish.Decrypt( h );
MemoryStream ms = new MemoryStream();
BinaryWriter writer = new BinaryWriter( ms );
foreach( uint t in decrypted )
writer.Write( t );
writer.Flush();
ms.Position = 0;
return ms;
}
uint[] ReadUints(BinaryReader r, int count)
{
uint[] ret = new uint[count];
for (int i = 0; i < ret.Length; i++)
ret[i] = r.ReadUInt32();
return ret;
}
List<PackageEntry> ParseTdHeader(Stream s, out long dataStart)
{
List<PackageEntry> items = new List<PackageEntry>();
BinaryReader reader = new BinaryReader(s);
ushort numFiles = reader.ReadUInt16();
/*uint dataSize = */reader.ReadUInt32();
for (int i = 0; i < numFiles; i++)
items.Add(new PackageEntry(reader));
dataStart = s.Position;
return items;
}
public Stream GetContent(uint hash)
{
PackageEntry e;
if (!index.TryGetValue(hash, out e))
return null;
s.Seek( dataStart + e.Offset, SeekOrigin.Begin );
byte[] data = new byte[ e.Length ];
s.Read( data, 0, (int)e.Length );
return new MemoryStream(data);
}
public Stream GetContent(string filename)
{
return GetContent(PackageEntry.HashFilename(filename));
}
public IEnumerable<uint> AllFileHashes()
{
return index.Keys;
}
}
[Flags]
enum MixFileFlags : uint
{
Checksum = 0x10000,
Encrypted = 0x20000,
}
}