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Decryption and decompression fixes and changes #6

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merged 3 commits into from
Sep 2, 2024
Merged

Decryption and decompression fixes and changes #6

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cc549ec
decryption and decompression fixes mainly
CosmicDreamsOfCode Sep 2, 2024
dfba3f8
changes
CosmicDreamsOfCode Sep 2, 2024
f4d4604
changes 2
CosmicDreamsOfCode Sep 2, 2024
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9 changes: 9 additions & 0 deletions Galanthus/GameManager.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -156,4 +156,13 @@ public static string GetPath(string inName)
}
return s_toc.GetData(file);
}

public static List<string>? GetAssetListing()
{
if (s_toc?.Assets == null)
{
return null;
}
return s_toc.Assets;
}
}
173 changes: 110 additions & 63 deletions Galanthus/SdfToc.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -2,6 +2,7 @@
using System.Collections.Generic;
using System.Diagnostics;
using System.Diagnostics.CodeAnalysis;
using System.IO;
using System.Linq;
using Galanthus.Structs;
using Galanthus.Utils;
Expand All @@ -11,7 +12,7 @@ namespace Galanthus;

public class SdfToc : IDisposable
{
public IEnumerable<Asset> Assets => m_assets.Values;
public List<string> Assets => m_assets.Keys.ToList();

private TocHeader m_header;
private List<Locale> m_locales;
Expand Down Expand Up @@ -207,34 +208,16 @@ public SdfToc(TocHeader inHeader, List<Locale> inLocales, List<Block<byte>> inDd

if (isEncrypted)
{
if (KeyManager.Key is null || KeyManager.Iv is null)
Block<byte> tempBuffer = new(compressedFileTable.Ptr, compressedFileTable.Size);
tempBuffer.MarkMemoryAsFragile();

if (!DecryptBlock(header.Version, compressedFileTable, ref tempBuffer))
{
Console.WriteLine($"Toc failed to decrypt!");
return null;
}

if (header.Version >= 0x29 && compressedFileTable.Size >= 8)
{
// first they use XTEA encryption, then they use des encryption
XTEA((uint*)compressedFileTable.Ptr, 32);

// DES-PCBC
// Problem is c# doesnt have native support for it
if (Crypto.DecryptDes((nuint)compressedFileTable.Ptr, (compressedFileTable.Size >> 3) << 3, (nuint)compressedFileTable.Ptr, (nuint)KeyManager.Key.Ptr,
(nuint)KeyManager.Iv.Ptr) != 0)
{
return null;
}
}
else if (compressedFileTable.Size >= 0x100)
{
// AES-192-OFB
// Problem is c# doesnt have native support for it
if (Crypto.DecryptAes((nuint)compressedFileTable.Ptr, 0x100, (nuint)compressedFileTable.Ptr, (nuint)KeyManager.Key.Ptr,
(nuint)KeyManager.Iv.Ptr) != 0)
{
return null;
}
}
tempBuffer.Dispose();
}

Block<byte> fileTable = new(header.FileTableDecompressedSize);
Expand Down Expand Up @@ -359,17 +342,18 @@ public bool TryGetDataFile(DataSlice inSlice, [NotNullWhen(true)] out string? pa
path = GameManager.GetPath($"sdf{s}{part}{s}{inSlice.Index:D4}{s}{locale}.sdfdata");
}

return true;
return File.Exists(path);
}


public unsafe Block<byte>? GetData(Asset inAsset)
{
// get final file size
int outBufferSize = 0;
int ddsHeaderSize = 0;
if (inAsset.DdsIndex != -1)
{
outBufferSize += m_ddsHeaders[inAsset.DdsIndex].Size;
ddsHeaderSize = m_ddsHeaders[inAsset.DdsIndex].Size;
}

foreach (DataSlice dataSlice in inAsset.DataSlices)
Expand All @@ -380,8 +364,14 @@ public bool TryGetDataFile(DataSlice inSlice, [NotNullWhen(true)] out string? pa
}

outBufferSize += (int)dataSlice.DecompressedSize;
}

// probably a localised file that isn't installed so just return null before we do anything
if (outBufferSize - ddsHeaderSize <= 0)
{
return null;
}

Block<byte> outBuffer = new(outBufferSize);

// add dds header data
Expand All @@ -405,39 +395,6 @@ public bool TryGetDataFile(DataSlice inSlice, [NotNullWhen(true)] out string? pa
Block<byte> compressedBuffer = new((int)dataSlice.CompressedSize);
stream.ReadExactly(compressedBuffer);

// decrypt slice
if (dataSlice.IsEncrypted)
{
if (KeyManager.Key is null || KeyManager.Iv is null)
{
return null;
}

if (m_header.Version >= 0x29 && compressedBuffer.Size >= 8)
{
// first they use XTEA encryption, then they use des encryption
XTEA((uint*)compressedBuffer.Ptr, 32);

// DES-PCBC
// Problem is c# doesnt have native support for it
if (Crypto.DecryptDes((nuint)compressedBuffer.Ptr, (compressedBuffer.Size >> 3) << 3, (nuint)compressedBuffer.Ptr, (nuint)KeyManager.Key.Ptr,
(nuint)KeyManager.Iv.Ptr) != 0)
{
return null;
}
}
else if (compressedBuffer.Size >= 0x100)
{
// AES-192-OFB
// Problem is c# doesnt have native support for it
if (Crypto.DecryptAes((nuint)compressedBuffer.Ptr, 0x100, (nuint)compressedBuffer.Ptr, (nuint)KeyManager.Key.Ptr,
(nuint)KeyManager.Iv.Ptr) != 0)
{
return null;
}
}
}

// decompress slice if needed
if (dataSlice.IsCompressed)
{
Expand All @@ -448,11 +405,33 @@ public bool TryGetDataFile(DataSlice inSlice, [NotNullWhen(true)] out string? pa
for (int i = 0; i < dataSlice.PageSizes!.Count; i++)
{
int decompressedSize = (int)Math.Min(dataSlice.DecompressedSize - decompressedOffset, pageSize);
if (dataSlice.PageSizes.Count == 1)
{
decompressedSize = (int)dataSlice.DecompressedSize;
}

if (dataSlice.PageSizes[i] == 0 || decompressedSize == dataSlice.PageSizes[i])
{
// uncompressed page
compressedBuffer.CopyTo(outBuffer, decompressedSize);
// set up temp buffer with only the page data
Block<byte> tempBuffer = new(compressedBuffer.Ptr, decompressedSize);
tempBuffer.MarkMemoryAsFragile();

// decrypt page
if (dataSlice.IsEncrypted)
{
if (!DecryptBlock(m_header.Version, tempBuffer, ref outBuffer))
{
Console.WriteLine("Page failed to decrypt!");
return null;
}
}
else
{
tempBuffer.CopyTo(outBuffer, decompressedSize);
}

tempBuffer.Dispose();
compressedBuffer.Shift(decompressedSize);
}
else
Expand All @@ -462,9 +441,30 @@ public bool TryGetDataFile(DataSlice inSlice, [NotNullWhen(true)] out string? pa
Block<byte> tempBuffer = new(compressedBuffer.Ptr, dataSlice.PageSizes[i]);
tempBuffer.MarkMemoryAsFragile();

// decrypt page
if (dataSlice.IsEncrypted)
{
if (!DecryptBlock(m_header.Version, tempBuffer, ref tempBuffer))
{
Console.WriteLine("Page failed to decrypt!");
return null;
}
}

if (!dataSlice.IsOodle)
{
ZStd.Decompress(tempBuffer, ref outBuffer);
switch (GameManager.CompressionMethod)
{
case CompressionMethod.ZLib:
ZLib.Decompress(tempBuffer, ref outBuffer);
break;
case CompressionMethod.ZStd:
ZStd.Decompress(tempBuffer, ref outBuffer);
break;
case CompressionMethod.Lz4:
Lz4.Decompress(tempBuffer, ref outBuffer);
break;
}
}
else
{
Expand All @@ -484,7 +484,20 @@ public bool TryGetDataFile(DataSlice inSlice, [NotNullWhen(true)] out string? pa
}
else
{
compressedBuffer.CopyTo(outBuffer, (int)dataSlice.DecompressedSize);
// decrypt whole slice
if (dataSlice.IsEncrypted)
{
if (!DecryptBlock(m_header.Version, compressedBuffer, ref outBuffer))
{
Console.WriteLine("Slice failed to decrypt!");
return null;
}
}
else
{
compressedBuffer.CopyTo(outBuffer, (int)dataSlice.DecompressedSize);
}

outBuffer.Shift((int)dataSlice.DecompressedSize);
}

Expand Down Expand Up @@ -644,6 +657,40 @@ private static void ParseEntry(DataStream inStream, bool isSigned, string name,
}
}

public static unsafe bool DecryptBlock(uint inVersion, Block<Byte> inBuf, ref Block<Byte> outBuf)
{
if (KeyManager.Key is null || KeyManager.Iv is null)
{
return false;
}

if (inVersion >= 0x29 && inBuf.Size >= 8)
{
// first they use XTEA encryption, then they use des encryption
XTEA((uint*)inBuf.Ptr, 32);

// DES-PCBC
// Problem is c# doesnt have native support for it
if (Crypto.DecryptDes((nuint)inBuf.Ptr, (inBuf.Size >> 3) << 3, (nuint)outBuf.Ptr, (nuint)KeyManager.Key.Ptr,
(nuint)KeyManager.Iv.Ptr) != 0)
{
return false;
}
}
else if (inBuf.Size >= 0x100)
{
// AES-192-OFB
// Problem is c# doesnt have native support for it
if (Crypto.DecryptAes((nuint)inBuf.Ptr, 0x100, (nuint)outBuf.Ptr, (nuint)KeyManager.Key.Ptr,
(nuint)KeyManager.Iv.Ptr) != 0)
{
return false;
}
}

return true;
}

public static unsafe void XTEA(uint* v, uint numRounds)
{
uint[] key = [0xb, 0x11, 0x17, 0x1f];
Expand Down
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