morkt 4969c7023e generalized CPZ archives access.
support different encryption schemes.
2015-12-12 18:25:50 +04:00

517 lines
20 KiB
C#

//! \file ArcCPZ.cs
//! \date Tue Nov 24 11:27:23 2015
//! \brief Purple Software resource archive.
//
// Copyright (C) 2015 by morkt
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to
// deal in the Software without restriction, including without limitation the
// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
// sell copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
// IN THE SOFTWARE.
//
using System;
using System.Collections.Generic;
using System.ComponentModel.Composition;
using System.IO;
using System.Linq;
using GameRes.Utility;
using System.Security.Cryptography;
namespace GameRes.Formats.Purple
{
[Serializable]
public class CmvsScheme
{
public uint[] Cpz5Secret;
public Cmvs.Md5Variant Md5Variant;
public uint DecoderFactor;
public uint EntryInitKey;
public byte EntryTailKey;
}
internal class CpzEntry : Entry
{
public uint CheckSum;
public uint Key;
public uint DirKey;
}
internal class CpzHeader
{
public int DirCount;
public int DirEntriesSize;
public int FileEntriesSize;
public uint[] CmvsMd5 = new uint[4];
public uint MasterKey;
public bool IsEncrypted;
public bool IsCompressed;
}
internal class CpzArchive : ArcFile
{
public CpzHeader Header;
public Cpz5Decoder Decoder;
public CpzArchive (ArcView arc, ArchiveFormat impl, ICollection<Entry> dir, CpzHeader header, Cpz5Decoder decoder)
: base (arc, impl, dir)
{
Header = header;
Decoder = decoder;
}
}
[Serializable]
public class CpzScheme : ResourceScheme
{
public Dictionary<string, CmvsScheme> KnownSchemes;
}
[Export(typeof(ArchiveFormat))]
public class CpzOpener : ArchiveFormat
{
public override string Tag { get { return "CPZ"; } }
public override string Description { get { return "Purple Software resource archive"; } }
public override uint Signature { get { return 0x355A5043; } } // 'CPZ5'
public override bool IsHierarchic { get { return true; } }
public override bool CanCreate { get { return false; } }
public static Dictionary<string, CmvsScheme> KnownSchemes = new Dictionary<string, CmvsScheme>();
public override ResourceScheme Scheme
{
get { return new CpzScheme { KnownSchemes = KnownSchemes }; }
set { KnownSchemes = ((CpzScheme)value).KnownSchemes; }
}
public override ArcFile TryOpen (ArcView file)
{
if (null == KnownSchemes)
throw new OperationCanceledException ("Outdated encryption schemes database");
var header = file.View.ReadBytes (0, 0x3C);
var checksum = file.View.ReadUInt32 (0x3C);
if (checksum != CheckSum (header, 0, 0x3C, 0x923A564Cu))
return null;
var cpz = new CpzHeader
{
DirCount = -0x1C5AC27 ^ LittleEndian.ToInt32 (header, 4),
DirEntriesSize = 0x37F298E7 ^ LittleEndian.ToInt32 (header, 8),
FileEntriesSize = 0x7A6F3A2C ^ LittleEndian.ToInt32 (header, 0x0C),
MasterKey = 0xAE7D39BF ^ LittleEndian.ToUInt32 (header, 0x30),
IsEncrypted = 0 != (0xFB73A955 ^ LittleEndian.ToUInt32 (header, 0x34)),
IsCompressed = 0 != (0x37ACF831 ^ LittleEndian.ToUInt32 (header, 0x38)),
};
var cmvs_md5 = new uint[] {
0x43DE7C19 ^ LittleEndian.ToUInt32 (header, 0x20),
0xCC65F415 ^ LittleEndian.ToUInt32 (header, 0x24),
0xD016A93C ^ LittleEndian.ToUInt32 (header, 0x28),
0x97A3BA9A ^ LittleEndian.ToUInt32 (header, 0x2C),
};
int index_size = cpz.DirEntriesSize + cpz.FileEntriesSize;
var index = file.View.ReadBytes (0x40, (uint)index_size);
if (index.Length != index_size)
return null;
var md5 = MD5.Create();
var hash = md5.ComputeHash (index);
if (!header.Skip (0x10).Take (0x10).SequenceEqual (hash))
return null;
foreach (var scheme in KnownSchemes.Values)
{
// both CmvsMd5 and index will be altered by ReadIndex in decryption attempt
Array.Copy (cmvs_md5, cpz.CmvsMd5, 4);
var arc = ReadIndex (file, scheme, cpz, index);
if (null != arc)
return arc;
file.View.Read (0x40, index, 0, (uint)index_size);
}
throw new UnknownEncryptionScheme();
}
ArcFile ReadIndex (ArcView file, CmvsScheme scheme, CpzHeader cpz, byte[] index)
{
var cmvs_md5 = Cmvs.MD5.Create (scheme.Md5Variant);
cmvs_md5.Compute (cpz.CmvsMd5);
DecryptIndexStage1 (index, cpz.MasterKey ^ 0x3795B39A, scheme.Cpz5Secret);
var decoder = new Cpz5Decoder (scheme, cpz.MasterKey, cpz.CmvsMd5[1]);
decoder.Decode (index, 0, cpz.DirEntriesSize, 0x3A);
var key = new uint[4];
key[0] = cpz.CmvsMd5[0] ^ (cpz.MasterKey + 0x76A3BF29);
key[1] = cpz.CmvsMd5[1] ^ cpz.MasterKey;
key[2] = cpz.CmvsMd5[2] ^ (cpz.MasterKey + 0x10000000);
key[3] = cpz.CmvsMd5[3] ^ cpz.MasterKey;
DecryptIndexDirectory (index, cpz.DirEntriesSize, key);
decoder.Init (cpz.MasterKey, cpz.CmvsMd5[2]);
int base_offset = 0x40 + index.Length;
int dir_offset = 0;
var dir = new List<Entry>();
for (int i = 0; i < cpz.DirCount; ++i)
{
int dir_size = LittleEndian.ToInt32 (index, dir_offset);
if (dir_size <= 0x10 || dir_size > index.Length)
return null;
int file_count = LittleEndian.ToInt32 (index, dir_offset+4);
if (file_count >= 0x10000)
return null;
int entries_offset = LittleEndian.ToInt32 (index, dir_offset+8);
uint dir_key = LittleEndian.ToUInt32 (index, dir_offset+0xC);
var dir_name = Binary.GetCString (index, dir_offset+0x10, dir_size-0x10);
int next_entries_offset;
if (i + 1 == cpz.DirCount)
next_entries_offset = cpz.FileEntriesSize;
else
next_entries_offset = LittleEndian.ToInt32 (index, dir_offset + dir_size + 8);
int cur_entries_size = next_entries_offset - entries_offset;
if (cur_entries_size <= 0)
return null;
int cur_offset = cpz.DirEntriesSize + entries_offset;
int cur_entries_end = cur_offset + cur_entries_size;
decoder.Decode (index, cur_offset, cur_entries_size, 0x7E);
key[0] = cpz.CmvsMd5[0] ^ dir_key;
key[1] = cpz.CmvsMd5[1] ^ (dir_key + 0x112233);
key[2] = cpz.CmvsMd5[2] ^ dir_key;
key[3] = cpz.CmvsMd5[3] ^ (dir_key + 0x34258765);
DecryptIndexEntry (index, cur_offset, cur_entries_size, key);
bool is_root_dir = dir_name == "root";
dir.Capacity = dir.Count + file_count;
for (int j = 0; j < file_count; ++j)
{
int entry_size = LittleEndian.ToInt32 (index, cur_offset);
if (entry_size > index.Length || entry_size <= 0x18)
return null;
var name = Binary.GetCString (index, cur_offset+0x18, cur_entries_end-(cur_offset+0x18));
if (!is_root_dir)
name = Path.Combine (dir_name, name);
var entry = FormatCatalog.Instance.Create<CpzEntry> (name);
entry.Offset = LittleEndian.ToInt64 (index, cur_offset+4) + base_offset;
entry.Size = LittleEndian.ToUInt32 (index, cur_offset+0xC);
entry.CheckSum = LittleEndian.ToUInt32 (index, cur_offset+0x10);
entry.Key = LittleEndian.ToUInt32 (index, cur_offset+0x14);
entry.DirKey = dir_key;
if (!entry.CheckPlacement (file.MaxOffset))
return null;
dir.Add (entry);
cur_offset += entry_size;
}
dir_offset += dir_size;
}
if (cpz.IsEncrypted)
decoder.Init (cpz.CmvsMd5[3], cpz.MasterKey);
return new CpzArchive (file, this, dir, cpz, decoder);
}
public override Stream OpenEntry (ArcFile arc, Entry entry)
{
var carc = arc as CpzArchive;
var cent = entry as CpzEntry;
if (null == carc || null == cent)
return base.OpenEntry (arc, entry);
var data = carc.File.View.ReadBytes (entry.Offset, entry.Size);
if (carc.Header.IsEncrypted)
{
uint key = (carc.Header.MasterKey ^ (cent.DirKey + cent.Key)) + (uint)carc.Header.DirCount - 0x5C29E87B;
carc.Decoder.DecryptEntry (data, carc.Header.CmvsMd5, key);
}
if (data.Length > 0x30 && Binary.AsciiEqual (data, 0, "PS2A"))
data = UnpackPs2 (data);
else if (data.Length > 0x40 && Binary.AsciiEqual (data, 0, "PB3B"))
DecryptPb3 (data);
return new MemoryStream (data);
}
void DecryptIndexStage1 (byte[] data, uint key, uint[] secret)
{
var sectet_key = new uint[24];
int secret_length = Math.Min (24, secret.Length);
for (int i = 0; i < secret_length; ++i)
sectet_key[i] = secret[i] - key;
uint shift = key;
shift = (shift >> 8) ^ key;
shift = (shift >> 8) ^ key;
shift = (shift >> 8) ^ key;
shift = (shift >> 8) ^ key;
shift = ((shift ^ 0xB) & 0xF) + 7;
unsafe
{
fixed (byte* raw = data)
{
uint* data32 = (uint*)raw;
int i = 5;
for (int n = data.Length / 4; n > 0; --n)
{
*data32 = Binary.RotR ((sectet_key[i] ^ *data32) + 0x784C5962, (int)shift) + 0x01010101;
++data32;
i = (i + 1) % 24;
}
byte* data8 = (byte*)data32;
for (int n = data.Length & 3; n > 0; --n)
{
*data8 = (byte)((*data8 ^ (sectet_key[i] >> (n * 4))) - 0x79);
++data8;
i = (i + 1) % 24;
}
}
}
}
void DecryptIndexDirectory (byte[] data, int length, uint[] key)
{
uint seed = 0x76548AEF;
unsafe
{
fixed (byte* raw = data)
{
uint* data32 = (uint*)raw;
int i;
for (i = 0; i < length / 4; ++i)
{
*data32 = Binary.RotL ((*data32 ^ key[i & 3]) - 0x4A91C262, 3) - seed;
++data32;
seed += 0x10FB562A;
}
byte* data8 = (byte*)data32;
for (int j = length & 3; j > 0; --j)
{
*data8 = (byte)((*data8 ^ (key[i++ & 3] >> 6)) + 0x37);
++data8;
}
}
}
}
void DecryptIndexEntry (byte[] data, int offset, int length, uint[] key)
{
if (offset < 0 || offset > data.Length)
throw new ArgumentOutOfRangeException ("offset");
if (length < 0 || length > data.Length || length > data.Length-offset)
throw new ArgumentException ("length");
uint seed = 0x2A65CB4E;
unsafe
{
fixed (byte* raw = &data[offset])
{
uint* data32 = (uint*)raw;
int i;
for (i = 0; i < length / 4; ++i)
{
*data32 = Binary.RotL ((*data32 ^ key[i & 3]) - seed, 2) + 0x37A19E8B;
++data32;
seed -= 0x139FA9B;
}
byte* data8 = (byte*)data32;
for (int j = length & 3; j > 0; --j)
{
*data8 = (byte)((*data8 ^ (key[i++ & 3] >> 4)) + 5);
++data8;
}
}
}
}
public static uint CheckSum (byte[] data, int index, int length, uint crc)
{
if (null == data)
throw new ArgumentNullException ("data");
if (index < 0 || index > data.Length)
throw new ArgumentOutOfRangeException ("index");
if (length < 0 || length > data.Length || length > data.Length-index)
throw new ArgumentException ("length");
int dwords = length / 4;
if (dwords > 0)
{
unsafe
{
fixed (byte* raw = &data[index])
{
uint* raw32 = (uint*)raw;
for (int i = 0; i < dwords; ++i)
crc += raw32[i];
}
}
index += length & -4;
}
for (int i = 0; i < (length & 3); ++i)
crc += data[index+i];
return crc;
}
byte[] UnpackPs2 (byte[] data)
{
DecryptPs2 (data);
byte[] frame = new byte[0x800];
int frame_pos = 0x7DF;
int unpacked_size = LittleEndian.ToInt32 (data, 0x28);
byte[] output = new byte[0x30+unpacked_size];
Buffer.BlockCopy (data, 0, output, 0, 0x30);
int src = 0x30;
int dst = 0x30;
int ctl = 1;
while (dst < output.Length && src < data.Length)
{
if (1 == ctl)
ctl = data[src++] | 0x100;
if (0 != (ctl & 1))
{
byte b = data[src++];
output[dst++] = b;
frame[frame_pos++] = b;
frame_pos &= 0x7FF;
}
else
{
int lo = data[src++];
int hi = data[src++];
int offset = lo | (hi & 0xE0) << 3;
int count = (hi & 0x1F) + 2;
for (int i = 0; i < count; ++i)
{
byte b = frame[(offset + i) & 0x7FF];
output[dst++] = b;
frame[frame_pos++] = b;
frame_pos &= 0x7FF;
}
}
ctl >>= 1;
}
return output;
}
void DecryptPs2 (byte[] data)
{
uint key = LittleEndian.ToUInt32 (data, 12);
int shift = (int)(key >> 20) % 5 + 1;
key = (key >> 24) + (key >> 3);
for (int i = 0x30; i < data.Length; ++i)
{
data[i] = Binary.RotByteR ((byte)(key ^ (data[i] - 0x7Cu)), shift);
}
}
void DecryptPb3 (byte[] data)
{
byte key1 = data[data.Length-3];
byte key2 = data[data.Length-2];
int src = data.Length - 0x2F;
for (int i = 8; i < 0x34; i += 2)
{
data[i ] ^= key1;
data[i ] -= data[src++];
data[i+1] ^= key2;
data[i+1] -= data[src++];
}
}
}
internal class Cpz5Decoder
{
protected byte[] m_decode_table = new byte[0x100];
protected CmvsScheme m_scheme;
public Cpz5Decoder (CmvsScheme scheme, uint key, uint summand)
{
m_scheme = scheme;
Init (key, summand);
}
public void Init (uint key, uint summand)
{
for (int i = 0; i < 0x100; ++i)
m_decode_table[i] = (byte)i;
for (int i = 0; i < 0x100; ++i)
{
uint i0 = (key >> 16) & 0xFF;
uint i1 = key & 0xFF;
var tmp = m_decode_table[i0];
m_decode_table[i0] = m_decode_table[i1];
m_decode_table[i1] = tmp;
i0 = (key >> 8) & 0xFF;
i1 = key >> 24;
tmp = m_decode_table[i0];
m_decode_table[i0] = m_decode_table[i1];
m_decode_table[i1] = tmp;
key = summand + m_scheme.DecoderFactor * Binary.RotR (key, 2);
}
}
public void Decode (byte[] data, int offset, int length, byte key)
{
for (int i = 0; i < length; ++i)
data[offset+i] = m_decode_table[key ^ data[offset+i]];
}
public void DecryptEntry (byte[] data, uint[] cmvs_md5, uint seed)
{
if (null == data)
throw new ArgumentNullException ("data");
if (null == cmvs_md5 || cmvs_md5.Length < 4)
throw new ArgumentException ("cmvs_md5");
int secret_length = Math.Min (m_scheme.Cpz5Secret.Length, 0x10) * sizeof(uint);
byte[] key_bytes = new byte[secret_length];
uint[] secret_key = new uint[0x10];
uint key = cmvs_md5[1] >> 2;
Buffer.BlockCopy (m_scheme.Cpz5Secret, 0, key_bytes, 0, secret_length);
for (int i = 0; i < secret_length; ++i)
key_bytes[i] = (byte)(key ^ m_decode_table[key_bytes[i]]);
Buffer.BlockCopy (key_bytes, 0, secret_key, 0, secret_length);
for (int i = 0; i < secret_key.Length; ++i)
secret_key[i] ^= seed;
unsafe
{
fixed (byte* raw = data)
{
uint* data32 = (uint*)raw;
key = m_scheme.EntryInitKey;
int k = 9;
for (int i = data.Length / 4; i > 0; --i)
{
*data32 = cmvs_md5[key & 3] ^ ((*data32 ^ secret_key[(key >> 6) & 0xf] ^ (secret_key[k] >> 1)) - seed);
k = (k + 1) & 0xf;
key += seed + *data32++;
}
byte* data8 = (byte*)data32;
for (int i = data.Length & 3; i > 0; --i)
{
*data8 = m_decode_table[*data8 ^ m_scheme.EntryTailKey];
++data8;
}
}
}
}
}
}