public static P2PCommand CreateCommand(string identity, string commandName, int nonce, BasePayload payload)
{
var command = new P2PCommand();
command.Prefix = DefaultPrefixBytes;
command.Suffix = DefaultSuffixBytes;
command.Identity = identity;
command.Nonce = nonce;
command.CommandName = commandName;
if (payload != null)
{
var bytes = payload.Serialize();
command.Payload = bytes;
command.Size = bytes.Length;
command.Checksum = GetChecksum(bytes);
}
else
{
var bytes = new byte[0];
command.Payload = bytes;
command.Size = bytes.Length;
command.Checksum = GetChecksum(bytes);
}
return(command);
}
public static P2PCommand ConvertBytesToMessage(byte[] bytes)
{
var prefixBytes = new byte[4];
var suffixBytes = new byte[4];
Array.Copy(bytes, 0, prefixBytes, 0, prefixBytes.Length);
Array.Copy(bytes, bytes.Length - suffixBytes.Length, suffixBytes, 0, suffixBytes.Length);
if (!BytesEquals(DefaultPrefixBytes, prefixBytes) || !BytesEquals(DefaultSuffixBytes, suffixBytes))
{
return(null);
}
var identityBytes = new byte[16];
var commandBytes = new byte[12];
var nonceBytes = new byte[4];
var sizeBytes = new byte[4];
Array.Copy(bytes, 4, identityBytes, 0, 16);
Array.Copy(bytes, 20, commandBytes, 0, 12);
Array.Copy(bytes, 32, nonceBytes, 0, 4);
Array.Copy(bytes, 36, sizeBytes, 0, 4);
if (BitConverter.IsLittleEndian)
{
Array.Reverse(nonceBytes);
Array.Reverse(sizeBytes);
}
var commandTextBytes = new List <byte>();
foreach (var b in commandBytes)
{
if (b > 0x00)
{
commandTextBytes.Add(b);
}
else
{
break;
}
}
var commandName = Encoding.UTF8.GetString(commandTextBytes.ToArray());
int nonce = BitConverter.ToInt32(nonceBytes, 0);
int size = BitConverter.ToInt32(sizeBytes, 0);
var payloadBytes = new byte[size];
var checksumBytes = new byte[4];
Array.Copy(bytes, 40, payloadBytes, 0, size);
Array.Copy(bytes, 40 + size, checksumBytes, 0, 4);
if (!BytesEquals(checksumBytes, GetChecksum(payloadBytes)))
{
return(null);
}
var command = new P2PCommand();
command.Prefix = prefixBytes;
command.Identity = new Guid(identityBytes).ToString();
command.CommandName = commandName;
command.Nonce = nonce;
command.Size = size;
command.Payload = payloadBytes;
command.Checksum = checksumBytes;
command.Suffix = suffixBytes;
return(command);
}
