ArcFile Open(byte[] basename, ArcView file, EncryptionScheme scheme, Key key)
{
uint key1 = scheme.BaseKey.Key1;
uint key2 = scheme.BaseKey.Key2;
for (int b = 0, e = basename.Length-1; e >= 0; ++b, --e)
{
key1 ^= basename[e];
key2 ^= basename[b];
key1 = Binary.RotR (key1, 7);
key2 = Binary.RotL (key2, 7);
}
if (null != key)
{
key1 ^= key.Key1;
key2 ^= key.Key2;
}
uint code = file.View.ReadUInt32 (4) ^ key2;
int index_size = (int)(code & 0xffffff);
byte flags = (byte)(code >> 24);
if (0 != (flags & 1))
index_size = (index_size << 11) - 8;
if (index_size < 5 || index_size >= file.MaxOffset)
return null;
var index = new byte[index_size];
if (index_size != file.View.Read (8, index, 0, (uint)index_size))
return null;
DecryptIndex (index, index_size, key2, scheme.RotatePattern);
var lpk_info = new LpkInfo
{
AlignedOffset = 0 != (flags & 1),
Flag1 = 0 != (flags & 2),
IsEncrypted = 0 != (flags & 4),
PackedEntries = 0 != (flags & 8),
WholeCrypt = 0 != (flags & 0x10),
Key = key1
};
var reader = new IndexReader (lpk_info);
var dir = reader.Read (index);
if (null == dir)
return null;
// this condition is fishy, probably patch files have additional bitflag set
if (lpk_info.WholeCrypt && Binary.AsciiEqual (basename, "PATCH"))
lpk_info.WholeCrypt = false;
return new LuciArchive (file, this, dir, scheme, reader.Info);
}
public LuciArchive(ArcView arc, ArchiveFormat impl, ICollection<Entry> dir, EncryptionScheme scheme, LpkInfo info)
: base(arc, impl, dir)
{
Info = info;
Scheme = scheme;
}
public override ArcFile TryOpen(ArcView file)
{
string name = Path.GetFileName (file.Name).ToUpperInvariant();
if (string.IsNullOrEmpty (name))
return null;
Key file_key = null;
var basename = Encodings.cp932.GetBytes (Path.GetFileNameWithoutExtension (name));
if (name != "SCRIPT.LPK")
CurrentFileMap.TryGetValue (name, out file_key);
try
{
var arc = Open (basename, file, CurrentScheme, file_key);
if (null != arc)
return arc;
}
catch { /* unknown encryption, ignore parse errors */ }
var new_scheme = QueryEncryptionScheme();
if (new_scheme == CurrentScheme && !CurrentScheme.ImportGameInit)
return null;
CurrentScheme = new_scheme;
if (name != "SCRIPT.LPK" && CurrentScheme.ImportGameInit)
{
if (0 == CurrentFileMap.Count)
ImportKeys (file.Name);
}
if (CurrentFileMap.Count > 0 && !CurrentFileMap.TryGetValue (name, out file_key))
return null;
return Open (basename, file, CurrentScheme, file_key);
}