static Smb2Compression()
{
compressorInstances = new Dictionary <CompressionAlgorithm, XcaCompressor>
{
[CompressionAlgorithm.LZNT1] = new LZNT1Compressor(),
[CompressionAlgorithm.LZ77] = new PlainLZ77Compressor(),
[CompressionAlgorithm.LZ77Huffman] = new LZ77HuffmanCompressor()
};
decompressorInstances = new Dictionary <CompressionAlgorithm, XcaDecompressor>
{
[CompressionAlgorithm.LZNT1] = new LZNT1Decompressor(),
[CompressionAlgorithm.LZ77] = new PlainLZ77Decompressor(),
[CompressionAlgorithm.LZ77Huffman] = new LZ77HuffmanDecompressor()
};
var pattern = new SMB2_COMPRESSION_PATTERN_PAYLOAD_V1();
PatternPayloadLength = TypeMarshal.GetBlockMemorySize(pattern);
var payloadHeader = new SMB2_COMPRESSION_PAYLOAD_HEADER();
FieldSizeOriginalPayloadSize = TypeMarshal.GetBlockMemorySize(payloadHeader.OriginalPayloadSize);
}
private static void ScanForPatternV1(byte[] data, out SMB2_COMPRESSION_PATTERN_PAYLOAD_V1?forwardDataPattern, out SMB2_COMPRESSION_PATTERN_PAYLOAD_V1?backwardDataPattern)
{
forwardDataPattern = null;
backwardDataPattern = null;
int endPosition;
if (data.Length < 64)
{
return;
}
byte front = data[0];
int frontRepetition = 1;
for (int i = 1; i < data.Length; i++)
{
if (data[i] == front)
{
frontRepetition++;
}
else
{
break;
}
}
if (frontRepetition >= 64)
{
forwardDataPattern = new SMB2_COMPRESSION_PATTERN_PAYLOAD_V1()
{
Pattern = front,
Reserved1 = 0,
Reserved2 = 0,
Repetitions = (UInt32)frontRepetition,
};
}
endPosition = frontRepetition;
byte end = data[data.Length - 1];
int endRepetition = 1;
for (int i = data.Length - 2; i >= endPosition; i--)
{
if (data[i] == end)
{
endRepetition++;
}
else
{
break;
}
}
if (endRepetition >= 64)
{
backwardDataPattern = new SMB2_COMPRESSION_PATTERN_PAYLOAD_V1()
{
Pattern = end,
Reserved1 = 0,
Reserved2 = 0,
Repetitions = (UInt32)endRepetition,
};
}
}
