/// <summary>
/// Decrypts the KIFINT archives using the known archive type, install directory, and name of executable with
/// the V_CODE2 used to decrypt.
/// </summary>
/// <param name="type">The type of archive to look for and decrypt.</param>
/// <param name="installDir">The installation directory for both the archives and executable.</param>
/// <param name="vcode2">The V_CODE2 key obtained from the exe, used to decrypt the file names.</param>
/// <param name="callback">The optional callback for progress made during decryption.</param>
/// <returns>The <see cref="KifintLookup"/> merged with all loaded archives.</returns>
///
/// <exception cref="ArgumentNullException">
/// <paramref name="installDir"/> or <paramref name="vcode2"/> is null.
/// </exception>
/// <exception cref="ArgumentException">
/// <paramref name="type"/> is <see cref="KifintType.Unknown"/>.
/// </exception>
public static KifintLookup Decrypt(KifintType type, string installDir, string vcode2,
KifintProgressCallback callback = null)
{
if (vcode2 == null)
{
throw new ArgumentNullException(nameof(vcode2));
}
if (type == KifintType.Unknown)
{
throw new ArgumentException($"{nameof(type)} cannot be {nameof(KifintType.Unknown)}!", nameof(type));
}
KifintLookup lookup = new KifintLookup(type);
string wildcard = EnumInfo <KifintType> .GetAttribute <KifintWildcardAttribute>(type).Wildcard;
string[] files = Directory.GetFiles(installDir, wildcard);
KifintProgressArgs progress = new KifintProgressArgs {
ArchiveType = type,
ArchiveIndex = 0,
ArchiveCount = files.Length,
};
foreach (string kifintPath in files)
{
progress.ArchiveName = Path.GetFileName(kifintPath);
using (Stream stream = File.OpenRead(kifintPath))
lookup.Merge(Decrypt(type, stream, kifintPath, vcode2, progress, callback));
progress.ArchiveIndex++;
}
progress.EntryIndex = 0;
progress.EntryCount = 0;
callback?.Invoke(progress);
return(lookup);
}
/// <summary>
/// Decrypts the KIFINT archives using the known archive type, install directory, and name of executable with
/// the V_CODE2 used to decrypt.
/// </summary>
/// <param name="type">The type of archive to look for and decrypt.</param>
/// <param name="stream">The stream to the open KIFINT archive.</param>
/// <param name="installDir">The installation directory for both the archives and executable.</param>
/// <param name="exePath">The path to the executable to extract the V_CODE2 key from.</param>
/// <returns>The <see cref="KifintLookup"/> merged with all loaded archives.</returns>
///
/// <exception cref="ArgumentNullException">
/// <paramref name="stream"/>, <paramref name="kifintPath"/>, or <paramref name="exePath"/> is null.
/// </exception>
/// <exception cref="ObjectDisposedException">
/// The <paramref name="stream"/> is closed.
/// </exception>
private static Kifint Decrypt(KifintType type, Stream stream, string kifintPath, string vcode2,
KifintProgressArgs progress, KifintProgressCallback callback)
{
if (kifintPath == null)
{
throw new ArgumentNullException(nameof(kifintPath));
}
if (vcode2 == null)
{
throw new ArgumentNullException(nameof(vcode2));
}
BinaryReader reader = new BinaryReader(stream);
KIFHDR hdr = reader.ReadUnmanaged <KIFHDR>();
if (hdr.Signature != "KIF") // It's really a KIF INT file
{
throw new UnexpectedFileTypeException(kifintPath, "KIF");
}
KIFENTRY[] entries = reader.ReadUnmanagedArray <KIFENTRY>(hdr.EntryCount);
progress.EntryIndex = 0;
progress.EntryCount = entries.Length;
uint tocSeed = GenTocSeed(vcode2);
uint fileKey = 0;
bool decrypt = false;
// Obtain the decryption file key if one exists
for (int i = 0; i < hdr.EntryCount; i++)
{
if (entries[i].FileName == "__key__.dat")
{
fileKey = MersenneTwister.GenRand(entries[i].Length);
decrypt = true;
break;
}
}
const int ProgressThreshold = 500;
// Decrypt the KIFINT entries using the file key
if (decrypt)
{
for (uint i = 0; i < hdr.EntryCount; i++)
{
if (entries[i].FileName == "__key__.dat")
{
continue;
}
progress.EntryIndex++;
if (i % ProgressThreshold == 0)
{
callback?.Invoke(progress);
}
// Give the entry the correct name
UnobfuscateFileName(entries[i].FileNameRaw, tocSeed + i);
// Give apply the extra offset to be decrypted
entries[i].Offset += i;
// Decrypt the entry's length and offset
DecryptEntry(ref entries[i].Info, fileKey);
}
}
return(new Kifint(kifintPath, entries, decrypt, fileKey, type));
}
