private bool DecryptBaseFile(Stream outBaseFile)
{
var tempStream = new MemoryStream();
var ci = Get <XexCompressionInfo>();
// Incase its compressed
XexCompressedBaseFile compBlock;
#region Decrypt if encrypted
if (ci.EncryptionType == XexEncryptionType.Encrypted)
{
#region Calculate our key
var aes = Rijndael.Create();
aes.Padding = PaddingMode.None;
var ms = new MemoryStream(Header.AesKey);
var decryptKey = new byte[0x10];
using (var decrypt = new CryptoStream(ms, aes.CreateDecryptor(_retailKey2, new byte[0x10]), CryptoStreamMode.Read))
{
decrypt.Read(decryptKey, 0, 0x10);
}
#endregion
// Now decrypt our data
aes = Rijndael.Create();
aes.Padding = PaddingMode.None;
var dataStream = Binary.GetStream();
dataStream.Seek(DataOffset, SeekOrigin.Begin);
using (var decrypt = new CryptoStream(dataStream, aes.CreateDecryptor(decryptKey, new byte[0x10]), CryptoStreamMode.Read))
{
#region Decrypt non compressed
if (ci.CompressionType == XexCompressionType.NotCompressed)
{
// Loop through each section and decrypt
foreach (var block in ci.RawBlocks)
{
var buffer = new byte[block.DataSize];
decrypt.Read(buffer, 0, buffer.Length);
outBaseFile.Write(buffer, 0, buffer.Length);
outBaseFile.Write(new byte[block.ZeroSize], 0, block.ZeroSize);
}
// Set our length to image size
outBaseFile.Seek(0, SeekOrigin.Begin);
outBaseFile.SetLength(Header.ImageSize);
// Return true
return(true);
}
#endregion
#region Decrypt compressed
compBlock = ci.CompressedBaseFile;
var index = 0;
while (compBlock.DataSize != 0)
{
var testData = new byte[compBlock.DataSize];
dataStream.Read(testData, 0, compBlock.DataSize);
dataStream.Seek(compBlock.DataSize * -1, SeekOrigin.Current);
// Decrypt our data size
var buffer = new byte[compBlock.DataSize];
decrypt.Read(buffer, 0, buffer.Length);
// Verify our hash
var hash = SHA1.Create().ComputeHash(buffer);
for (var x = 0; x < 0x14; x++)
{
if (hash[x] != compBlock.Hash[x])
{
throw new Exception("Bad hash");
}
}
// Write each block
tempStream.Write(buffer, 0, compBlock.DataSize);
compBlock = ModelFactory.GetModel <XexCompressedBaseFile>(buffer);
index = index + 1;
}
tempStream.Seek(0, SeekOrigin.Begin);
#endregion
}
dataStream.Close();
}
else
{
#region Write out non compressed
if (ci.CompressionType == XexCompressionType.NotCompressed)
{
// Loop through each section and decrypt
foreach (var block in ci.RawBlocks)
{
var buffer = Binary.ReadBytes((int)DataOffset, block.DataSize);
outBaseFile.Write(buffer, 0, buffer.Length);
outBaseFile.Write(new byte[block.ZeroSize], 0, block.ZeroSize);
}
// Set our length to image size
outBaseFile.Seek(0, SeekOrigin.Begin);
outBaseFile.SetLength(Header.ImageSize);
// Return true
return(true);
}
#endregion
// Since we didnt write to the temp stream
// lets just take it from the file
}
#endregion
// Time to work with compresed
var sizeLeft = (int)Header.ImageSize;
compBlock = ci.CompressedBaseFile;
#region Handle Delta Compresed
if (ci.CompressionType == XexCompressionType.DeltaCompressed)
{
while (compBlock.DataSize != 0)
{
var buffer = new byte[compBlock.DataSize];
tempStream.Read(buffer, 0, buffer.Length);
outBaseFile.Write(buffer, 0, compBlock.DataSize);
compBlock = ModelFactory.GetModel <XexCompressedBaseFile>(buffer);
}
// Seek back to start
outBaseFile.Seek(0, SeekOrigin.Begin);
// return
return(true);
}
#endregion
#region Decompress if compressed
#region Create Decompression Ctx
int maxSize = 0x8000, ctx = -1, unknown = 0;
XCompress.LzxDecompress lzx;
lzx.CpuType = 1;
lzx.WindowSize = ci.CompressedBaseFile.CompressionWindow;
IntPtr allocate = Marshal.AllocHGlobal(0x23200);
if (XCompress.LDICreateDecompression(ref maxSize, ref lzx,
0, 0, allocate, ref unknown, ref ctx) != 0)
{
throw new Exception("Failed to create decompression");
}
#endregion
while (compBlock.DataSize != 0)
{
var buffer = new byte[compBlock.DataSize];
tempStream.Read(buffer, 0, buffer.Length);
compBlock = ModelFactory.GetModel <XexCompressedBaseFile>(buffer);
var offset = compBlock.OffsetTableSize;
#region Decompress
while (true)
{
int compressedLen = BitConverter.ToUInt16(buffer, offset);
if (compressedLen == 0)
{
break;
}
offset += 2;
var compressedData = new byte[compressedLen];
Buffer.BlockCopy(buffer, offset, compressedData, 0, compressedLen);
offset += compressedLen;
var decompressedLength = (sizeLeft < 0x8000) ? sizeLeft : 0x8000;
var decompressedData = new byte[decompressedLength];
if (XCompress.LDIDecompress(ctx, compressedData,
compressedLen, decompressedData, ref decompressedLength) != 0)
{
throw new Exception("Failed to decompress");
}
outBaseFile.Write(decompressedData, 0, decompressedLength);
sizeLeft -= decompressedLength;
}
#endregion
}
#region Destroy ctx
if (XCompress.LDIDestroyDecompression(ctx) != 0)
{
throw new Exception("Failed to destroy decompression");
}
Marshal.FreeHGlobal(allocate);
#endregion
#endregion
// Move back to the begining
outBaseFile.Seek(0, SeekOrigin.Begin);
outBaseFile.SetLength(Header.ImageSize);
// All done
return(true);
}
