2014-07-21 23:26:28 +04:00

289 lines
10 KiB
C#

//! \file ArcINT.cs
//! \date Fri Jul 11 09:32:36 2014
//! \brief Frontwing games archive.
//
using System;
using System.IO;
using System.Linq;
using System.Text;
using System.ComponentModel.Composition;
using System.Collections.Generic;
using System.Diagnostics;
using Simias.Encryption;
using System.Runtime.InteropServices;
using GameRes.Formats.Strings;
using GameRes.Formats.Properties;
namespace GameRes.Formats
{
public class FrontwingArchive : ArcFile
{
public readonly Blowfish Encryption;
public FrontwingArchive (ArcView arc, ArchiveFormat impl, ICollection<Entry> dir, Blowfish cipher)
: base (arc, impl, dir)
{
Encryption = cipher;
}
}
public class IntEncryptionInfo
{
public uint? Key { get; set; }
public string Scheme { get; set; }
public string Password { get; set; }
public IntEncryptionInfo () { }
}
[Export(typeof(ArchiveFormat))]
public class IntOpener : ArchiveFormat
{
public override string Tag { get { return "INT"; } }
public override string Description { get { return "FrontWing game resource archive"; } }
public override uint Signature { get { return 0x0046494b; } }
public override ArcFile TryOpen (ArcView file)
{
uint entry_count = file.View.ReadUInt32 (4);
if (0 == entry_count || 0 != ((entry_count - 1) >> 0x14))
{
Trace.WriteLine (string.Format ("Invalid entry count ({0})", entry_count));
return null;
}
if (file.View.AsciiEqual (8, "__key__.dat\x00"))
{
uint? key = QueryEncryptionInfo();
if (null == key)
throw new UnknownEncryptionScheme();
return OpenEncrypted (file, entry_count, key.Value);
}
long current_offset = 8;
var dir = new List<Entry>();
for (uint i = 0; i < entry_count; ++i)
{
string name = file.View.ReadString (current_offset, 0x40);
var entry = FormatCatalog.Instance.CreateEntry (name);
entry.Offset = file.View.ReadUInt32 (current_offset+0x40);
entry.Size = file.View.ReadUInt32 (current_offset+0x44);
if (!entry.CheckPlacement (file.MaxOffset))
return null;
dir.Add (entry);
current_offset += 0x48;
}
return new ArcFile (file, this, dir);
}
private ArcFile OpenEncrypted (ArcView file, uint entry_count, uint main_key)
{
if (1 == entry_count)
return null; // empty archive
long current_offset = 8;
var twister = new Twister();
// [@@L1] = 32-bit key
// [@@L1+4] = 0 if key is available, -1 otherwise
uint key_data = file.View.ReadUInt32 (current_offset+0x44);
uint twist_key = twister.Twist (key_data);
// [@@L0] = 32-bit twist key
byte[] blowfish_key = BitConverter.GetBytes (twist_key);
if (!BitConverter.IsLittleEndian)
Array.Reverse (blowfish_key);
var blowfish = new Blowfish (blowfish_key);
var dir = new List<Entry>();
byte[] name_info = new byte[0x40];
for (uint i = 1; i < entry_count; ++i)
{
current_offset += 0x48;
file.View.Read (current_offset, name_info, 0, 0x40);
uint eax = file.View.ReadUInt32 (current_offset+0x40);
uint edx = file.View.ReadUInt32 (current_offset+0x44);
eax += i;
blowfish.Decipher (ref eax, ref edx);
uint key = twister.Twist (main_key + i);
string name = DecipherName (name_info, key);
var entry = FormatCatalog.Instance.CreateEntry (name);
entry.Offset = eax;
entry.Size = edx;
if (!entry.CheckPlacement (file.MaxOffset))
return null;
dir.Add (entry);
}
return new FrontwingArchive (file, this, dir, blowfish);
}
private Stream OpenEncryptedEntry (FrontwingArchive arc, Entry entry)
{
using (var view = arc.File.CreateViewAccessor (entry.Offset, entry.Size))
{
byte[] data = new byte[entry.Size];
// below is supposedly faster version of
//arc.File.View.Read (entry.Offset, data, 0, entry.Size);
unsafe
{
byte* ptr = view.GetPointer (entry.Offset);
try {
Marshal.Copy (new IntPtr(ptr), data, 0, data.Length);
} finally {
view.SafeMemoryMappedViewHandle.ReleasePointer();
}
}
arc.Encryption.Decipher (data, data.Length/8*8);
return new MemoryStream (data, false);
}
}
public override Stream OpenEntry (ArcFile arc, Entry entry)
{
if (arc is FrontwingArchive)
return OpenEncryptedEntry (arc as FrontwingArchive, entry);
else
return base.OpenEntry (arc, entry);
}
public string DecipherName (byte[] name, uint key)
{
key += (key >> 8) + (key >> 16) + (key >> 24);
key &= 0xff;
key %= 0x34;
int count = 0;
for (int i = 0; i < name.Length; ++i)
{
byte al = name[i];
if (0 == al)
break;
byte bl = (byte)key;
++count;
uint edx = al;
al |= 0x20;
al -= 0x61;
if (al < 0x1a)
{
if (0 != (edx & 0x20))
al += 0x1a;
al = (byte)~al;
al += 0x34;
if (al >= bl)
al -= bl;
else
al = (byte)(al - bl + 0x34);
if (al >= 0x1a)
al += 6;
al += 0x41;
name[i] = al;
}
++key;
if (0x34 == key)
key = 0;
}
return Encodings.cp932.GetString (name, 0, count);
}
class Twister
{
const uint TwisterLength = 0x270;
uint[] m_twister = new uint[TwisterLength];
uint m_twister_pos = 0;
public uint Twist (uint key)
{
Init (key);
return Next();
}
public void Init (uint key)
{
uint edx = key;
for (int i = 0; i < TwisterLength; ++i)
{
uint ecx = edx * 0x10dcd + 1;
m_twister[i] = (edx & 0xffff0000) | (ecx >> 16);
edx *= 0x1C587629;
edx += 0x10dce;
}
m_twister_pos = 0;
}
public uint Next ()
{
uint ecx = m_twister[m_twister_pos];
uint edx = m_twister_pos + 1;
if (TwisterLength == edx)
edx = 0;
uint edi = m_twister[edx];
edi = ((edi ^ ecx) & 0x7FFFFFFF) ^ ecx;
bool carry = 0 != (edi & 1);
edi >>= 1;
if (carry)
edi ^= 0x9908B0DF;
ecx = m_twister_pos + 0x18d;
if (ecx >= TwisterLength)
ecx -= TwisterLength;
edi ^= m_twister[ecx];
m_twister[m_twister_pos] = edi;
m_twister_pos = edx;
uint eax = edi ^ (edi >> 11);
eax = ((eax & 0xFF3A58AD) << 7) ^ eax;
eax = ((eax & 0xFFFFDF8C) << 15) ^ eax;
eax = (eax >> 18) ^ eax;
return eax;
}
}
public static uint EncodePassPhrase (string password)
{
byte[] pass_bytes = Encodings.cp932.GetBytes (password);
uint key = 0xffffffff;
foreach (var c in pass_bytes)
{
uint val = (uint)c << 24;
key ^= val;
for (int i = 0; i < 8; ++i)
{
bool carry = 0 != (key & 0x80000000);
key <<= 1;
if (carry)
key ^= 0x4C11DB7;
}
key = ~key;
}
return key;
}
public struct KeyData
{
public uint Key;
public string Passphrase;
}
public static readonly Dictionary<string, KeyData> KnownSchemes = new Dictionary<string, KeyData> {
{ "Grisaia no Kajitsu", new KeyData { Key=0x1DAD9120, Passphrase="FW-6JD55162" }},
{ "Shukufuku no Campanella", new KeyData { Key=0x4260E643, Passphrase="CAMPANELLA" }},
{ "Makai Tenshi Djibril -Episode 4-", new KeyData { Key=0xA5A166AA, Passphrase="FW_MAKAI-TENSHI_DJIBRIL4" }},
{ "Sengoku Tenshi Djibril (trial)", new KeyData { Key=0xef870610, Passphrase="FW-8O9B6WDS" }},
};
IntEncryptionInfo m_info = Settings.Default.INTEncryption ?? new IntEncryptionInfo();
uint? QueryEncryptionInfo ()
{
var widget = new GUI.WidgetINT (m_info);
var args = new ParametersRequestEventArgs
{
Notice = arcStrings.INTNotice,
InputWidget = widget,
};
FormatCatalog.Instance.InvokeParametersRequest (this, args);
if (!args.InputResult)
throw new OperationCanceledException();
Settings.Default.INTEncryption = widget.Info;
return widget.GetKey();
}
}
}