public Message Parse(byte[] payload)
{
if (payload == null)
{
throw new ArgumentNullException(nameof(payload));
}
if (payload.Length < 24)
{
throw new ParseMessageException(ErrorCodes.InvalidCommandLength);
}
var header = payload.Take(40); // Extract the header.
var startStringPayload = header.Take(4);
var network = Networks.MainNet;
if (startStringPayload.SequenceEqual(new byte[] { 0xf9, 0xbe, 0xb4, 0xd9 }))
{
network = Networks.MainNet;
}
else if (startStringPayload.SequenceEqual(new byte[] { 0x0b, 0x11, 0x09, 0x07 }))
{
network = Networks.TestNet;
}
else if (startStringPayload.SequenceEqual(new byte[] { 0xfa, 0xbf, 0xb5, 0xda }))
{
network = Networks.RegTest;
}
else
{
throw new ParseMessageException(ErrorCodes.InvalidStartString);
}
var commandNamePayload = header.Skip(4).Take(12).Where(b => b != 0x00).ToArray();
var commandName = System.Text.Encoding.ASCII.GetString(commandNamePayload);
var ipv6 = header.Skip(16).Take(16);
var payloadSizePayload = header.Skip(32).Take(4).ToArray();
var payloadSize = BitConverter.ToInt32(payloadSizePayload, 0);
var checkSum = header.Skip(36).Take(4);
byte[] contentPayload = null;
if (payloadSize > 0)
{
contentPayload = payload.Skip(40).Take(payloadSize).ToArray();
SHA256 mySHA256 = SHA256.Create();
var newCheckSum = mySHA256.ComputeHash(mySHA256.ComputeHash(contentPayload)).Take(4);
if (!newCheckSum.SequenceEqual(checkSum))
{
throw new ParseMessageException(ErrorCodes.InvalidChecksum);
}
}
else if (!checkSum.SequenceEqual(new byte[] { 0x5d, 0xf6, 0xe0, 0xe2 }))
{
throw new ParseMessageException(ErrorCodes.InvalidChecksum);
}
if (!Constants.MessageNameLst.Contains(commandName))
{
throw new ParseMessageException(ErrorCodes.InvalidCommandName);
}
Message message = null;
if (commandName == Constants.MessageNames.Ping)
{
var nonce = BitConverter.ToUInt64(contentPayload, 0);
message = new PingMessage(nonce, network);
}
else if (commandName == Constants.MessageNames.Addr)
{
message = AddrMessage.Deserialize(contentPayload, network);
}
else if (commandName == Constants.MessageNames.Version)
{
message = VersionMessage.Deserialize(contentPayload, network);
}
else if (commandName == Constants.MessageNames.Verack)
{
message = new VerackMessage(network);
}
else if (commandName == Constants.MessageNames.GetAddr)
{
message = new GetAddressMessage(network);
}
else if (commandName == Constants.MessageNames.Inventory)
{
message = InventoryMessage.Deserialize(contentPayload, network);
}
else if (commandName == Constants.MessageNames.Transaction)
{
message = TransactionMessage.Deserialize(contentPayload, network, Transactions.TransactionTypes.NoneCoinbase);
}
else if (commandName == Constants.MessageNames.Pong)
{
var nonce = BitConverter.ToUInt64(contentPayload, 0);
message = new PongMessage(nonce, network);
}
else if (commandName == Constants.MessageNames.MemPool)
{
message = new MemPoolMessage(network);
}
else if (commandName == Constants.MessageNames.GetData)
{
message = GetDataMessage.Deserialize(contentPayload, network);
}
else if (commandName == Constants.MessageNames.Block)
{
message = BlockMessage.Deserialize(contentPayload, network);
}
else if (commandName == Constants.MessageNames.GetBlocks)
{
message = GetBlocksMessage.Deserialize(contentPayload, network);
}
else if (commandName == Constants.MessageNames.NotFound)
{
message = NotFoundMessage.Deserialize(contentPayload, network);
}
message.MessageHeader.Ipv6 = ipv6.ToArray();
return(message);
}