private int getDataLengthFromMessageHeader(List <byte> header)
{
int data_length = -1;
// we should have the full header, save the data length
using (MemoryStream m = new MemoryStream(header.ToArray()))
{
using (BinaryReader reader = new BinaryReader(m))
{
reader.ReadByte(); // skip start byte
int code = reader.ReadInt32(); // skip message code
data_length = reader.ReadInt32(); // finally read data length
byte[] data_checksum = reader.ReadBytes(32); // skip checksum sha512qu/sha512sq, 32 bytes
byte checksum = reader.ReadByte(); // header checksum byte
byte endByte = reader.ReadByte(); // end byte
if (endByte != 'I')
{
Logging.warn("Header end byte was not 'I'");
return(-1);
}
if (CoreProtocolMessage.getHeaderChecksum(header.Take(41).ToArray()) != checksum)
{
Logging.warn(String.Format("Header checksum mismatch"));
return(-1);
}
if (data_length <= 0)
{
Logging.warn(String.Format("Data length was {0}, code {1}", data_length, code));
return(-1);
}
if (data_length > CoreConfig.maxMessageSize)
{
Logging.warn(String.Format("Received data length was bigger than max allowed message size - {0}, code {1}.", data_length, code));
return(-1);
}
}
}
return(data_length);
}