public override Stream OpenEntry(ArcFile arc, Entry entry)
{
var g2ent = entry as G2Entry;
if (null == g2ent)
{
return(base.OpenEntry(arc, entry));
}
int entry_size = (int)g2ent.Size;
int offset = 0;
var decoders = new G2Scheme[4];
for (int i = 0; i < 4 && offset < entry_size; ++i)
{
decoders[i] = G2MetaScheme.CreateInstance(g2ent.Keys[i]);
if (null != decoders[i])
{
offset += EntryChunkSize;
}
}
var output = new byte[entry_size];
var input = new byte[EntryChunkSize];
int current_decoder = 0;
offset = 0;
while (offset < entry_size)
{
int current_chunk_size = Math.Min(EntryChunkSize, entry_size - offset);
if (null != decoders[current_decoder])
{
arc.File.View.Read(g2ent.Offset + offset, input, 0, (uint)current_chunk_size);
decoders[current_decoder].Decrypt(input, 0, output, offset, current_chunk_size);
}
else
{
arc.File.View.Read(g2ent.Offset + offset, output, offset, (uint)current_chunk_size);
}
current_decoder = (current_decoder + 1) & 3;
offset += current_chunk_size;
}
return(new MemoryStream(output));
}
public override ArcFile TryOpen(ArcView file)
{
var header = file.View.ReadBytes(0, 0x5C);
if (header.Length != 0x5C)
{
return(null);
}
header = HeaderEncryption.Decrypt(header);
if (!Binary.AsciiEqual(header, "GLibArchiveData2.") || header[0x12] != 0)
{
return(null);
}
int version = header[0x11] - '0';
if (version != 0 && version != 1)
{
return(null);
}
uint index_offset = LittleEndian.ToUInt32(header, 0x54);
uint index_size = LittleEndian.ToUInt32(header, 0x58);
byte[][] encrypted_index = new byte[2][];
encrypted_index[0] = file.View.ReadBytes(index_offset, index_size);
if (encrypted_index[0].Length != index_size)
{
return(null);
}
encrypted_index[1] = new byte[index_size];
uint[] keys =
{
LittleEndian.ToUInt32(header, 0x44),
LittleEndian.ToUInt32(header, 0x34),
LittleEndian.ToUInt32(header, 0x24),
LittleEndian.ToUInt32(header, 0x14),
};
int i = 0;
foreach (var key in keys)
{
var decoder = G2MetaScheme.CreateInstance(key);
decoder.Decrypt(encrypted_index[i], encrypted_index[i ^ 1]);
i ^= 1;
}
byte[] index = encrypted_index[i];
if (!Binary.AsciiEqual(index, "CDBD"))
{
return(null);
}
int count = LittleEndian.ToInt32(index, 4);
int current_offset = 0x10;
int info_base = current_offset + LittleEndian.ToInt32(index, 8);
int names_base = current_offset + count * 0x18;
var dir = new List <Entry> (count);
for (i = 0; i < count; ++i)
{
int name_offset = names_base + LittleEndian.ToInt32(index, current_offset);
int parent_dir = LittleEndian.ToInt32(index, current_offset + 8);
int attr = LittleEndian.ToInt32(index, current_offset + 0xC);
var name = Binary.GetCString(index, name_offset, info_base - name_offset);
if (parent_dir != -1)
{
name = Path.Combine(dir[parent_dir].Name, name);
}
var entry = new G2Entry {
Name = name
};
if (0x100 == attr)
{
int info_offset = info_base + LittleEndian.ToInt32(index, current_offset + 0x10);
entry.Size = LittleEndian.ToUInt32(index, info_offset + 8);
entry.Offset = LittleEndian.ToUInt32(index, info_offset + 0xC);
entry.Type = FormatCatalog.Instance.GetTypeFromName(name);
for (int j = 0; j < 4; ++j)
{
info_offset += 0x10;
entry.Keys[j] = LittleEndian.ToUInt32(index, info_offset);
}
}
dir.Add(entry);
current_offset += 0x18;
}
return(new ArcFile(file, this, dir.Where(e => e.Offset != -1).ToList()));
}
