/// <summary>
/// Extracts the KIFINT entry to a fixed stream of <paramref name="kifintStream"/>.
/// </summary>
/// <param name="kifintStream">The stream to the open KIFINT archive.</param>
/// <param name="entry">The KIFINT entry used to locate the file.</param>
/// <param name="leaveOpen">
/// True if the KIFINT archive stream should be left open even after closing the returned stream.
/// </param>
/// <returns>
/// A fixed stream containing the data of the decrypted entry. This stream must always be disposed of, because
/// it's not guaranteed to be a fixed stream of <paramref name="kifintStream"/>. This is the case when the
/// length is small enough for extracting bytes to be more efficient.
/// </returns>
///
/// <exception cref="ArgumentNullException">
/// <paramref name="kifintStream"/> or <paramref name="entry"/> is null.
/// </exception>
internal static Stream ExtractToStream(KifintStream kifintStream, KifintEntry entry, bool leaveOpen)
{
if (kifintStream == null)
{
throw new ArgumentNullException(nameof(kifintStream));
}
if (entry == null)
{
throw new ArgumentNullException(nameof(entry));
}
var kifint = entry.Kifint;
// Smaller streams will be faster as reading a big chunk of data all at once.
if (kifint.IsEncrypted && entry.Length < 131072 * 2) // Some arbitrary power of 2 cutoff length
{
try {
return(new MemoryStream(ExtractToBytes(kifintStream, entry)));
} finally {
// We need to make sure the the stream is closed by us if we're not
// relying on the fixed streams to close the KIFINT archive stream.
if (!leaveOpen)
{
kifintStream.Close();
}
}
}
kifintStream.Open(kifint);
kifintStream.Position = entry.Offset;
if (kifint.IsEncrypted)
{
return(new BlowfishInputStream(kifint.Blowfish, kifintStream, entry.Length, leaveOpen));
}
return(new FixedStream(kifintStream, entry.Length, leaveOpen));
}
/// <summary>
/// Extracts the KIFINT entry file from the the entry's KIFINT archive.
/// </summary>
/// <param name="kifintStream">The stream to the open KIFINT archive.</param>
/// <param name="entry">The KIFINT entry used to locate the file.</param>
/// <returns>A byte array containing the extracted KIFINT entry's file data.</returns>
///
/// <exception cref="ArgumentNullException">
/// <paramref name="kifintStream"/> or <paramref name="entry"/> is null.
/// </exception>
internal static byte[] ExtractToBytes(KifintStream kifintStream, KifintEntry entry)
{
if (kifintStream == null)
{
throw new ArgumentNullException(nameof(kifintStream));
}
if (entry == null)
{
throw new ArgumentNullException(nameof(entry));
}
var kifint = entry.Kifint;
kifintStream.Open(kifint);
BinaryReader reader = new BinaryReader(kifintStream);
kifintStream.Position = entry.Offset;
byte[] buffer = reader.ReadBytes(entry.Length);
if (kifint.IsEncrypted)
{
kifint.Blowfish.Decrypt(buffer, entry.Length & ~7);
}
return(buffer);
}
