(RCT): lookup image password in start.mjo game file.

This commit is contained in:
morkt 2017-01-09 02:27:01 +04:00
parent 6959cb7ebd
commit a14c781ae3

View File

@ -25,9 +25,11 @@
using System;
using System.IO;
using System.Linq;
using System.Text;
using System.Collections.Generic;
using System.ComponentModel.Composition;
using System.Diagnostics;
using System.Windows;
using System.Windows.Media;
using System.Windows.Media.Imaging;
@ -286,10 +288,96 @@ namespace GameRes.Formats.Majiro
private string QueryPassword ()
{
if (VFS.IsVirtual)
{
var password = FindImageKey();
if (!string.IsNullOrEmpty (password))
return password;
}
var options = Query<RctOptions> (arcStrings.ArcImageEncrypted);
return options.Password;
}
static readonly Lazy<ArchiveFormat> s_Majiro = new Lazy<ArchiveFormat> (() => FormatCatalog.Instance.ArcFormats.FirstOrDefault (x => x.Tag == "MAJIRO"));
private string FindImageKey ()
{
var arc_fs = VFS.Top as ArchiveFileSystem;
if (null == arc_fs)
return null;
try
{
// look for "start.mjo" within "scenario.arc" archive
var src_name = arc_fs.Source.File.Name;
var scenario_arc_name = Path.Combine (Path.GetDirectoryName (src_name), "scenario.arc");
if (!File.Exists (scenario_arc_name))
return null;
byte[] script;
using (var file = new ArcView (scenario_arc_name))
using (var arc = s_Majiro.Value.TryOpen (file))
{
if (null == arc)
return null;
var start_mjo = arc.Dir.First (e => e.Name == "start.mjo");
using (var mjo = arc.OpenEntry (start_mjo))
{
script = new byte[mjo.Length];
mjo.Read (script, 0, script.Length);
}
}
if (Binary.AsciiEqual (script, "MajiroObjX1.000"))
DecryptMjo (script);
else if (!Binary.AsciiEqual (script, "MjPlainBytecode"))
return null;
// locate key within start.mjo script
int n = script.ToInt32 (0x18);
for (int offset = 0x20 + n * 8; offset < script.Length - 4; ++offset)
{
offset = Array.IndexOf<byte> (script, 1, offset);
if (-1 == offset)
break;
if (8 != script[offset+1])
continue;
int str_length = script.ToUInt16 (offset+2);
if (0 == str_length || str_length + 12 > script.Length - offset
|| 0x0835 != script.ToUInt16 (offset+str_length+4)
|| 0x7A7B6ED4 != script.ToUInt32 (offset+str_length+6))
continue;
offset += 4;
int end = Array.IndexOf<byte> (script, 0, offset, str_length);
if (-1 != end)
str_length = end - offset;
var password = Encodings.cp932.GetString (script, offset, str_length);
Trace.WriteLine (string.Format ("Found key in start.mjo [{0}]", password), "[RCT]");
return password;
}
}
catch { /* ignore errors */ }
return null;
}
private void DecryptMjo (byte[] data)
{
int offset = 0x1C + 8 * data.ToInt32 (0x18);
if (offset < 0x1C || offset >= data.Length - 4)
return;
int count = data.ToInt32 (offset);
offset += 4;
if (count <= 0 || count > data.Length - offset)
return;
Debug.Assert (Crc32.Table.Length == 0x100);
unsafe
{
fixed (uint* table = Crc32.Table)
{
byte* key = (byte*)table;
for (int i = 0; i < count; ++i)
data[offset+i] ^= key[i & 0x3FF];
}
}
}
public override ResourceOptions GetDefaultOptions ()
{
return new RctOptions { Password = Settings.Default.RCTPassword };