/// <summary>
/// Deserializes the <see cref="XvEntryHeader"/> from the underlying <see cref="Stream"/> of the specified <see cref="BinaryReader"/>.
/// </summary>
/// <param name="reader">The <see cref="BinaryReader"/> to read from.</param>
/// <param name="key">The hash used to decrypt <see cref="XvEntryHeader"/> information.</param>
/// <returns>A new <see cref="XvEntryHeader"/> populated with the entry's data.</returns>
public static XvEntryHeader Deserialize(BinaryReader reader, ulong key)
{
//* get the basic entry information
XvEntryHeader header = ReadHeader(reader);
//* set the key incase it's not updated
header.RollingKey = key;
//* if the archive encrypts the meta data, decrypt it
//* thanks to daxxy
if ((header.Flags & XvEntryHeaderFlags.SafeHeader) != XvEntryHeaderFlags.SafeHeader)
{
ulong fileSizeKey = (key * XvArchive.ENTRY_KEY) ^ header.Hash,
dataOffsetKey = (fileSizeKey * XvArchive.ENTRY_KEY) ^ ~(header.Hash);
uint uncompressedKey = (uint)(fileSizeKey >> 32),
compressedKey = (uint)(fileSizeKey & 0xFFFFFFFF);
header.Size ^= uncompressedKey;
header.CompressedSize ^= compressedKey;
header.OffsetData ^= dataOffsetKey;
header.RollingKey = dataOffsetKey;
long returnPosition = reader.BaseStream.Position;
reader.BaseStream.Seek((long)(header.OffsetData + header.CompressedSize - IV_OFFSET), SeekOrigin.Begin);
header.IV = reader.ReadBytes(16);
header.CompressedSize -= IV_OFFSET;
reader.BaseStream.Seek(returnPosition, SeekOrigin.Begin);
}
return(header);
}
/// <summary>
///
/// </summary>
/// <param name="reader"></param>
/// <returns></returns>
private static XvEntryHeader ReadHeader(BinaryReader reader)
{
XvEntryHeader header = new XvEntryHeader {
Hash = reader.ReadUInt64(),
Size = reader.ReadUInt32(),
CompressedSize = reader.ReadUInt32(),
Flags = (XvEntryHeaderFlags)reader.ReadUInt32(),
OffsetName = reader.ReadUInt32(),
OffsetData = reader.ReadUInt64(),
OffsetFullPath = reader.ReadUInt32(),
LocalizeType = reader.ReadByte(),
LocalizeLocale = reader.ReadByte(),
Key = reader.ReadUInt16()
};
long returnPosition = reader.BaseStream.Position;
reader.BaseStream.Seek(header.OffsetName, SeekOrigin.Begin);
header.Name = reader.ReadStringNullTerminated();
reader.BaseStream.Seek(header.OffsetFullPath, SeekOrigin.Begin);
header.Path = reader.ReadStringNullTerminated();
reader.BaseStream.Seek(returnPosition, SeekOrigin.Begin);
return(header);
}
/// <summary>
///
/// </summary>
/// <param name="reader"></param>
/// <returns></returns>
public static XvEntryHeader Deserialize(BinaryReader reader)
{
XvEntryHeader header = ReadHeader(reader);
if ((header.Flags & XvEntryHeaderFlags.SafeHeader) != XvEntryHeaderFlags.SafeHeader)
{
throw new InvalidDataException("SAFE HEADER FLAG NOT SET BUT WRONG DESERIALIZE CALLED");
}
return(header);
}
