void DecryptIndexStage1(byte[] data, uint key, CmvsScheme scheme)
{
var secret = scheme.Cpz5Secret;
var secret_key = new uint[24];
int secret_length = Math.Min(24, secret.Length);
for (int i = 0; i < secret_length; ++i)
{
secret_key[i] = secret[i] - key;
}
int shift = (int)(((key >> 24) ^ (key >> 16) ^ (key >> 8) ^ key ^ 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((secret_key[i] ^ *data32) + scheme.IndexAddend, shift) + 0x01010101;
++data32;
i = (i + 1) % 24;
}
byte *data8 = (byte *)data32;
for (int n = data.Length & 3; n > 0; --n)
{
*data8 = (byte)((*data8 ^ (secret_key[i] >> (n * 4))) - scheme.IndexSubtrahend);
++data8;
i = (i + 1) % 24;
}
}
}
}
public Cpz5Decoder(CmvsScheme scheme, uint key, uint summand)
{
m_scheme = scheme;
Init(key, summand);
}
public Cpz5Decoder(CmvsScheme scheme, uint key, uint summand)
{
m_scheme = scheme;
Init (key, summand);
}
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);
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);
for (int j = 0; j < 4; ++j)
{
key[j] = cpz.CmvsMd5[j] ^ (dir_key + scheme.DirKeyAddend[j]);
}
DecryptIndexEntry(index, cur_offset, cur_entries_size, key, scheme.IndexSeed);
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) + 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));
}
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);
}
