/// <summary>
/// Initializes a new instance of the <see cref="MpqUnknownFile"/> class.
/// </summary>
internal MpqUnknownFile(MpqStream mpqStream, MpqFileFlags flags, MpqHash mpqHash, uint hashIndex, uint hashCollisions, uint?encryptionSeed = null)
: base(mpqHash.Name, mpqStream, flags, mpqHash.Locale, false)
{
if (mpqHash.Mask == 0)
{
throw new ArgumentException("Expected the Mask value of mpqHash argument to be set to a non-zero value.", nameof(mpqHash));
}
if (flags.HasFlag(MpqFileFlags.Encrypted) && encryptionSeed is null)
{
throw new ArgumentException($"Cannot encrypt an {nameof(MpqUnknownFile)} without an encryption seed.", nameof(flags));
}
_hashMask = mpqHash.Mask;
_hashIndex = hashIndex;
_hashCollisions = hashCollisions;
_encryptionSeed = encryptionSeed;
}
/// <summary>
/// Initializes a new instance of the <see cref="MpqStream"/> class.
/// </summary>
/// <param name="entry">The file's entry in the <see cref="BlockTable"/>.</param>
/// <param name="baseStream">The <see cref="MpqArchive"/>'s stream.</param>
/// <param name="blockSize">The <see cref="MpqArchive.BlockSize"/>.</param>
internal MpqStream(MpqEntry entry, Stream baseStream, int blockSize)
{
_mode = MpqStreamMode.Read;
_isStreamOwner = false;
_filePosition = entry.FilePosition;
_fileSize = entry.FileSize;
_compressedSize = entry.CompressedSize;
_flags = entry.Flags;
_isCompressed = (_flags & MpqFileFlags.Compressed) != 0;
_isEncrypted = _flags.HasFlag(MpqFileFlags.Encrypted);
_isSingleUnit = _flags.HasFlag(MpqFileFlags.SingleUnit);
_encryptionSeed = entry.EncryptionSeed;
_baseEncryptionSeed = entry.BaseEncryptionSeed;
_stream = baseStream;
_blockSize = blockSize;
if (_isSingleUnit)
{
// Read the entire file into memory
var filedata = new byte[_compressedSize];
lock (_stream)
{
_stream.Seek(_filePosition, SeekOrigin.Begin);
var read = _stream.Read(filedata, 0, filedata.Length);
if (read != filedata.Length)
{
throw new MpqParserException("Insufficient data or invalid data length");
}
}
if (_isEncrypted && _fileSize > 3)
{
if (_encryptionSeed == 0)
{
throw new MpqParserException("Unable to determine encryption key");
}
StormBuffer.DecryptBlock(filedata, _encryptionSeed);
}
_currentData = _flags.HasFlag(MpqFileFlags.CompressedMulti) && _compressedSize > 0
? DecompressMulti(filedata, _fileSize)
: filedata;
}
else
{
_currentBlockIndex = -1;
// Compressed files start with an array of offsets to make seeking possible
if (_isCompressed)
{
var blockposcount = (int)((_fileSize + _blockSize - 1) / _blockSize) + 1;
// Files with metadata have an extra block containing block checksums
if ((_flags & MpqFileFlags.FileHasMetadata) != 0)
{
blockposcount++;
}
_blockPositions = new uint[blockposcount];
lock (_stream)
{
_stream.Seek(_filePosition, SeekOrigin.Begin);
using (var br = new BinaryReader(_stream, new UTF8Encoding(), true))
{
for (var i = 0; i < blockposcount; i++)
{
_blockPositions[i] = br.ReadUInt32();
}
}
}
var blockpossize = (uint)blockposcount * 4;
/*
* if (_blockPositions[0] != blockpossize)
* {
* // _entry.Flags |= MpqFileFlags.Encrypted;
* throw new MpqParserException();
* }
*/
if (_isEncrypted && blockposcount > 1)
{
var maxOffset1 = (uint)_blockSize + blockpossize;
if (_encryptionSeed == 0)
{
// This should only happen when the file name is not known.
if (!entry.TryUpdateEncryptionSeed(_blockPositions[0], _blockPositions[1], blockpossize, maxOffset1))
{
throw new MpqParserException("Unable to determine encyption seed");
}
}
_encryptionSeed = entry.EncryptionSeed;
_baseEncryptionSeed = entry.BaseEncryptionSeed;
StormBuffer.DecryptBlock(_blockPositions, _encryptionSeed - 1);
if (_blockPositions[0] != blockpossize)
{
throw new MpqParserException($"Decryption failed{(string.IsNullOrEmpty(entry.FileName) ? string.Empty : $" for '{entry.FileName}'")} (block position 0).");
}
if (_blockPositions[1] > maxOffset1)
{
throw new MpqParserException($"Decryption failed{(string.IsNullOrEmpty(entry.FileName) ? string.Empty : $" for '{entry.FileName}'")} (block position 1).");
}
}
}
private Stream GetCompressedStream(Stream baseStream, MpqFileFlags targetFlags, MpqCompressionType compressionType, int targetBlockSize)
{
var resultStream = new MemoryStream();
var singleUnit = targetFlags.HasFlag(MpqFileFlags.SingleUnit);
void TryCompress(uint bytes)
{
var offset = baseStream.Position;
var compressedStream = compressionType switch
{
MpqCompressionType.ZLib => ZLibCompression.Compress(baseStream, (int)bytes, true),
_ => throw new NotSupportedException(),
};
// Add one because CompressionType byte not written yet.
var length = compressedStream.Length + 1;
if (!singleUnit && length >= bytes)
{
baseStream.CopyTo(resultStream, offset, (int)bytes, StreamExtensions.DefaultBufferSize);
}
else
{
resultStream.WriteByte((byte)compressionType);
compressedStream.Position = 0;
compressedStream.CopyTo(resultStream);
}
compressedStream.Dispose();
if (singleUnit)
{
baseStream.Dispose();
}
}
var length = (uint)baseStream.Length;
if ((targetFlags & MpqFileFlags.Compressed) == 0)
{
baseStream.CopyTo(resultStream);
}
else if (singleUnit)
{
TryCompress(length);
}
else
{
var blockCount = (uint)((length + targetBlockSize - 1) / targetBlockSize) + 1;
var blockOffsets = new uint[blockCount];
blockOffsets[0] = 4 * blockCount;
resultStream.Position = blockOffsets[0];
for (var blockIndex = 1; blockIndex < blockCount; blockIndex++)
{
var bytesToCompress = blockIndex + 1 == blockCount ? (uint)(baseStream.Length - baseStream.Position) : (uint)targetBlockSize;
TryCompress(bytesToCompress);
blockOffsets[blockIndex] = (uint)resultStream.Position;
}
resultStream.Position = 0;
using (var writer = new BinaryWriter(resultStream, new System.Text.UTF8Encoding(false, true), true))
{
for (var blockIndex = 0; blockIndex < blockCount; blockIndex++)
{
writer.Write(blockOffsets[blockIndex]);
}
}
}
resultStream.Position = 0;
return(resultStream);
}
internal Stream Transform(MpqFileFlags targetFlags, MpqCompressionType compressionType, uint targetFilePosition, int targetBlockSize)
{
using var memoryStream = new MemoryStream();
CopyTo(memoryStream);
memoryStream.Position = 0;
var fileSize = memoryStream.Length;
using var compressedStream = GetCompressedStream(memoryStream, targetFlags, compressionType, targetBlockSize);
var compressedSize = (uint)compressedStream.Length;
var resultStream = new MemoryStream();
var blockPosCount = (uint)(((int)fileSize + targetBlockSize - 1) / targetBlockSize) + 1;
if (targetFlags.HasFlag(MpqFileFlags.Encrypted) && blockPosCount > 1)
{
var blockPositions = new int[blockPosCount];
var singleUnit = targetFlags.HasFlag(MpqFileFlags.SingleUnit);
var hasBlockPositions = !singleUnit && ((targetFlags & MpqFileFlags.Compressed) != 0);
if (hasBlockPositions)
{
for (var blockIndex = 0; blockIndex < blockPosCount; blockIndex++)
{
using (var br = new BinaryReader(compressedStream, new UTF8Encoding(), true))
{
for (var i = 0; i < blockPosCount; i++)
{
blockPositions[i] = (int)br.ReadUInt32();
}
}
compressedStream.Seek(0, SeekOrigin.Begin);
}
}
else
{
if (singleUnit)
{
blockPosCount = 2;
}
blockPositions[0] = 0;
for (var blockIndex = 2; blockIndex < blockPosCount; blockIndex++)
{
blockPositions[blockIndex - 1] = targetBlockSize * (blockIndex - 1);
}
blockPositions[blockPosCount - 1] = (int)compressedSize;
}
var encryptionSeed = _baseEncryptionSeed;
if (targetFlags.HasFlag(MpqFileFlags.BlockOffsetAdjustedKey))
{
encryptionSeed = MpqEntry.AdjustEncryptionSeed(encryptionSeed, targetFilePosition, (uint)fileSize);
}
var currentOffset = 0;
using (var writer = new BinaryWriter(resultStream, new UTF8Encoding(false, true), true))
{
for (var blockIndex = hasBlockPositions ? 0 : 1; blockIndex < blockPosCount; blockIndex++)
{
var toWrite = blockPositions[blockIndex] - currentOffset;
var data = StormBuffer.EncryptStream(compressedStream, (uint)(encryptionSeed + blockIndex - 1), currentOffset, toWrite);
writer.Write(data);
currentOffset += toWrite;
}
}
}
else
{
compressedStream.CopyTo(resultStream);
}
resultStream.Position = 0;
return(resultStream);
}