// Compressed files start with an array of offsets to make seeking possible
private void LoadBlockPositions()
{
int blockposcount = (int)((mBlock.FileSize + mBlockSize - 1) / mBlockSize) + 1;
mBlockPositions = new uint[blockposcount];
lock (mStream)
{
mStream.Seek(mBlock.FilePos, SeekOrigin.Begin);
BinaryReader br = new BinaryReader(mStream);
for (int i = 0; i < blockposcount; i++)
mBlockPositions[i] = br.ReadUInt32();
}
uint blockpossize = (uint)blockposcount * 4;
#if true
// OW:
// If the archive if protected some way, perform additional check
// Sometimes, the file appears not to be encrypted, but it is.
// Edit: In WoW 1.10+, there's a new flag. With this flag present,
// there's one additional entry in the block table. If this flag
// is present, we skip this test to keep the file readable.
if ((mBlock.Flags & MpqFileFlags.FileHasMetadata) == 0)
{
if (mBlockPositions[0] != blockpossize)
mBlock.Flags |= MpqFileFlags.Encrypted;
}
if (mBlock.IsEncrypted)
{
if (mSeed1 == 0)
{
mSeed1 = MpqArchive.DetectFileSeed(mBlockPositions, blockpossize);
if (mSeed1 == 0)
throw new MpqParserException("Unable to determine encyption seed");
}
MpqArchive.DecryptBlock(mBlockPositions, mSeed1);
mSeed1++; // Add 1 because the first block is the offset list
}
#else
// StormLib takes this to mean the data is encrypted
if (mBlockPositions[0] != blockpossize)
{
if (mSeed1 == 0)
{
mSeed1 = MpqArchiveReader.DetectFileSeed(mBlockPositions, blockpossize);
if (mSeed1 == 0)
throw new Exception("Unable to determine encyption seed");
}
MpqArchiveReader.DecryptBlock(mBlockPositions, mSeed1);
mSeed1++; // Add 1 because the first block is the offset list
}
#endif
}
private byte[] LoadBlock(int BlockIndex, int ExpectedLength)
{
uint offset;
int toread;
if (mBlock.IsCompressed)
{
offset = mBlockPositions[BlockIndex];
toread = (int)(mBlockPositions[BlockIndex + 1] - offset);
}
else
{
offset = (uint)(BlockIndex * mBlockSize);
toread = ExpectedLength;
}
offset += mBlock.FilePos;
byte[] data = new byte[toread];
lock (mStream)
{
mStream.Seek(offset, SeekOrigin.Begin);
mStream.Read(data, 0, toread);
}
if (mBlock.IsEncrypted && mBlock.FileSize > 3)
{
if (mSeed1 == 0)
{
uint value0 = BitConverter.ToUInt32(data, 0);
uint value1 = BitConverter.ToUInt32(data, 4);
mSeed1 = MpqArchive.DetectFileSeed(value0, value1, 0x2fbfbbef, 0x3d3d3d2f); // .J unicode magic
if (mSeed1 == 0)
{
mSeed1 = MpqArchive.DetectFileSeed(value0, value1, 0x3d3d2f2f, 0x3d3d3d3d); // .J ascii
if (mSeed1 == 0)
{
mSeed1 = MpqArchive.DetectFileSeed(value0, value1, 0x46464952, mBlock.FileSize - 8); // RIFF
if (mSeed1 == 0) throw new MpqParserException("Unable to determine encryption key");
}
}
}
MpqArchive.DecryptBlock(data, (uint)(mSeed1 + BlockIndex));
}
if (mBlock.IsCompressed && data.Length != ExpectedLength)
{
if ((mBlock.Flags & MpqFileFlags.CompressedMulti) != 0)
data = DecompressMulti(data, ExpectedLength);
else
data = PKDecompress(new MemoryStream(data), ExpectedLength);
}
return data;
}
// Compressed files start with an array of offsets to make seeking possible
private void LoadBlockPositions()
{
int blockposcount = (int)((_entry.FileSize + _blockSize - 1) / _blockSize) + 1;
// Files with metadata have an extra block containing block checksums
if ((_entry.Flags & MpqFileFlags.FileHasMetadata) != 0)
{
blockposcount++;
}
_blockPositions = new uint[blockposcount];
lock (_stream)
{
_stream.Seek(_entry.FilePos, SeekOrigin.Begin);
BinaryReader br = new BinaryReader(_stream);
for (int i = 0; i < blockposcount; i++)
{
_blockPositions[i] = br.ReadUInt32();
}
}
uint blockpossize = (uint)blockposcount * 4;
/*
* if(_blockPositions[0] != blockpossize)
* _entry.Flags |= MpqFileFlags.Encrypted;
*/
if (_entry.IsEncrypted)
{
if (_entry.EncryptionSeed == 0) // This should only happen when the file name is not known
{
_entry.EncryptionSeed = MpqArchive.DetectFileSeed(_blockPositions[0], _blockPositions[1], blockpossize) + 1;
if (_entry.EncryptionSeed == 1)
{
throw new MpqParserException("Unable to determine encyption seed");
}
}
MpqArchive.DecryptBlock(_blockPositions, _entry.EncryptionSeed - 1);
if (_blockPositions[0] != blockpossize)
{
throw new MpqParserException("Decryption failed");
}
if (_blockPositions[1] > _blockSize + blockpossize)
{
throw new MpqParserException("Decryption failed");
}
}
}
