From 5d6438c2b67f5ef2b7b50bb2c2701f0c059d9a9a Mon Sep 17 00:00:00 2001 From: morkt Date: Sun, 12 Nov 2017 10:13:16 +0400 Subject: [PATCH] (ARCG): recognize BMX archives with external encrypted index. --- ArcFormats/Tanaka/ArcARCG.cs | 124 ++++++++++++++++++++++++++++++----- 1 file changed, 108 insertions(+), 16 deletions(-) diff --git a/ArcFormats/Tanaka/ArcARCG.cs b/ArcFormats/Tanaka/ArcARCG.cs index 5ed9b804..8f4141dc 100644 --- a/ArcFormats/Tanaka/ArcARCG.cs +++ b/ArcFormats/Tanaka/ArcARCG.cs @@ -28,6 +28,9 @@ using System.Collections.Generic; using System.ComponentModel.Composition; using System.IO; using System.Linq; +using System.Runtime.InteropServices; +using GameRes.Cryptography; +using GameRes.Utility; namespace GameRes.Formats.Will { @@ -49,37 +52,58 @@ namespace GameRes.Formats.Will { if (0x10000 != file.View.ReadUInt32 (4)) return null; - uint index_offset = file.View.ReadUInt32 (8); - uint index_size = file.View.ReadUInt32 (0xC); + int index_offset = file.View.ReadInt32 (8); + int index_size = file.View.ReadInt32 (0xC); int dir_count = file.View.ReadUInt16 (0x10); int count = file.View.ReadInt32 (0x12); - if (!IsSaneCount (count) || index_offset >= file.MaxOffset - || index_size > file.View.Reserve (index_offset, index_size)) + int base_offset = index_offset; + byte[] index = null; + if (0 == index_offset) + { + if (VFS.IsVirtual || !file.Name.HasExtension ("bmx")) + return null; + var bmi_name = Path.ChangeExtension (file.Name, "bmi"); + index = ReadIndex (bmi_name); + if (null == index || !index.AsciiEqual ("ARCG") || index.ToUInt32 (4) != 0x10000) + return null; + index_offset = index.ToInt32 (8); + index_size = index.ToInt32 (0xC); + dir_count = index.ToUInt16 (0x10); + count = index.ToInt32 (0x12); + base_offset = 0; + } + else + { + if (index_offset >= file.MaxOffset) + return null; + index = file.View.ReadBytes (index_offset, (uint)index_size); + } + if (!IsSaneCount (count) || index_size > index.Length) return null; - + int index_pos = index_offset - base_offset; var dir = new List (count); for (int j = 0; j < dir_count; ++j) { - uint name_length = file.View.ReadByte (index_offset); - var dir_name = file.View.ReadString (index_offset+1, name_length-1); - index_offset += name_length; - uint dir_offset = file.View.ReadUInt32 (index_offset); - int file_count = file.View.ReadInt32 (index_offset+4); - if (dir_offset >= file.MaxOffset || file_count < 0 || file_count > count) + int name_length = index[index_pos]; + var dir_name = Binary.GetCString (index, index_pos+1, name_length-1); + index_pos += name_length; + int dir_offset = index.ToInt32 (index_pos) - base_offset; + int file_count = index.ToInt32 (index_pos+4); + if (dir_offset < 0 || dir_offset >= index.Length || file_count < 0 || file_count > count) return null; - index_offset += 8; + index_pos += 8; for (int i = 0; i < file_count; ++i) { - name_length = file.View.ReadByte (dir_offset); + name_length = index[dir_offset]; if (0 == name_length) return null; - var file_name = file.View.ReadString (dir_offset+1, name_length-1); + var file_name = Binary.GetCString (index, dir_offset+1, name_length-1); file_name = file_name.Replace ('?', '？'); dir_offset += name_length; file_name = Path.Combine (dir_name, file_name); var entry = FormatCatalog.Instance.Create (file_name); - entry.Offset = file.View.ReadUInt32 (dir_offset); - entry.Size = file.View.ReadUInt32 (dir_offset+4); + entry.Offset = index.ToUInt32 (dir_offset); + entry.Size = index.ToUInt32 (dir_offset+4); if (!entry.CheckPlacement (file.MaxOffset)) return null; dir_offset += 8; @@ -100,6 +124,74 @@ namespace GameRes.Formats.Will return new ArcFile (file, this, dir); } + byte[] ReadIndex (string bmi_name) + { + var index = File.ReadAllBytes (bmi_name); + uint signature = index.ToUInt32 (0); + string passkey; + if (!KnownKeys.TryGetValue (signature, out passkey)) + { + var root = Path.GetPathRoot (bmi_name); + if (string.IsNullOrEmpty (root)) + return null; + uint serial; + if (!GetVolumeInformation (root, IntPtr.Zero, 0, out serial, + IntPtr.Zero, IntPtr.Zero, IntPtr.Zero, 0)) + return null; + passkey = string.Format ("{0:x4}{1}", serial, (int)serial); + } + uint seed = GetSeedFromString (passkey); + var twister = new MersenneTwister (seed); + unsafe + { + fixed (byte* idx8 = index) + { + uint* dst = (uint*)idx8; + for (int n = index.Length / 4; n > 0; --n) + { + *dst++ ^= twister.Rand(); + } + } + } + return index; + } + + uint GetSeedFromString (string passphrase) + { + if (string.IsNullOrEmpty (passphrase)) + return 0; + var buf = Encodings.cp932.GetBytes (passphrase); + int seed = (sbyte)buf[0]; + for (int i = 1; i < buf.Length; ++i) + seed *= (sbyte)buf[i]; + return (uint)seed; + } + + [DllImport("Kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)] + [return: MarshalAs(UnmanagedType.Bool)] + public extern static bool GetVolumeInformation( + string rootPathName, IntPtr volumeNameBuffer, int volumeNameSize, + out uint volumeSerialNumber, IntPtr maximumComponentLength, IntPtr fileSystemFlags, + IntPtr fileSystemNameBuffer, int nFileSystemNameSize); + + BmiScheme KnownSchemes = new BmiScheme(); + + public override ResourceScheme Scheme + { + get { return KnownSchemes; } + set { KnownSchemes = (BmiScheme)value; } + } + + internal IDictionary KnownKeys { + get { return KnownSchemes.KnownKeys ?? new Dictionary(); } + } + internal static Lazy BcFormat = new Lazy (() => ImageFormat.FindByTag ("BC")); } + + [Serializable] + public class BmiScheme : ResourceScheme + { + public IDictionary KnownKeys; + } }