private CommandBuilder(Connection connection, byte[] receivedBuffer)
{
m_ReceivedBuffer = receivedBuffer;
MemoryStream command = new MemoryStream(m_ReceivedBuffer);
byte[] header = new byte[Encoding.ASCII.GetByteCount(Constants.Protocol)];
command.Read(header, 0, header.Length);
if (!Encoding.ASCII.GetString(header).Equals(Constants.Protocol))
throw new InvalidDataException();
m_EncryptionMethod = (EncryptionMethod)command.ReadByte();
byte[] encryptedDataLength = new byte[2];
command.Read(encryptedDataLength, 0, encryptedDataLength.Length);
byte[] encryptedData = new byte[BitConverter.ToUInt16(encryptedDataLength, 0)];
if (encryptedData.Length > command.Position + encryptedData.Length)
throw new InvalidDataException();
command.Read(encryptedData, 0, encryptedData.Length);
switch (m_EncryptionMethod)
{
case EncryptionMethod.None:
m_CommandData = new MemoryStream(encryptedData);
break;
case EncryptionMethod.Rijndael:
m_CommandData = new MemoryStream(Core.RijndaelDecrypt(connection.ReceivingKey, encryptedData));
break;
case EncryptionMethod.RSA:
m_CommandData = new MemoryStream(Core.RSADecrypt(encryptedData));
break;
default:
throw new InvalidDataException();
}
}
public static Command Receive(Connection connection, byte[] receivedBuffer)
{
if (connection == null)
throw new ArgumentNullException("connection");
if (receivedBuffer == null)
throw new ArgumentNullException("buffer");
if (receivedBuffer.Length < 10)
throw new ArgumentException();
CommandBuilder command = new CommandBuilder(connection, receivedBuffer);
byte code = command.ReadByte();
command.SetCommandCode(code);
switch (code)
{
case 0x10:
return new Command10(command);
case 0x11:
return new Command11(command);
case 0x12:
return new Command12(command);
case 0x13:
return new Command13(command);
case 0x20:
return new Command20(command);
case 0x21:
return new Command21(command);
case 0x22:
return new Command22(command);
case 0x23:
return new Command23(command);
case 0x40:
return new Command40(command);
case 0x41:
return new Command41(command);
case 0x42:
return new Command42(command);
case 0x43:
return new Command43(command);
case 0x44:
return new Command44(command);
case 0x45:
return new Command45(command);
case 0x46:
return new Command46(command);
case 0x50:
return new Command50(command);
case 0x51:
return new Command51(command);
case 0x52:
return new Command52(command);
case 0x53:
return new Command53(command);
case 0x54:
return new Command54(command);
case 0x60:
return new Command60(command);
case 0x61:
return new Command61(command);
case 0x62:
return new Command62(command);
case 0x63:
return new Command63(command);
case 0x64:
return new Command64(command);
case 0x70:
return new Command70(command);
case 0x71:
return new Command71(command);
case 0x72:
return new Command72(command);
case 0x74:
return new Command74(command);
case 0x75:
return new Command75(command);
case 0x76:
return new Command76(command);
case 0x78:
return new Command78(command);
case 0x79:
return new Command79(command);
case 0x7A:
return new Command7A(command);
default:
throw new InvalidDataException();
}
}
public void Send(Connection connection)
{
byte[] encryptedData = m_CommandData.ToArray();
switch (m_EncryptionMethod)
{
case EncryptionMethod.Rijndael:
encryptedData = Core.RijndaelEncrypt(connection.SendingKey, m_CommandData.ToArray());
break;
case EncryptionMethod.RSA:
encryptedData = Core.RSAEncrypt(connection.PublicKey, m_CommandData.ToArray());
break;
}
MemoryStream command = new MemoryStream();
byte[] header = Encoding.ASCII.GetBytes(Constants.Protocol);
command.Write(header, 0, header.Length);
command.WriteByte((byte)m_EncryptionMethod);
command.Write(BitConverter.GetBytes((ushort)encryptedData.Length), 0, 2);
command.Write(encryptedData, 0, encryptedData.Length);
connection.Send(command.ToArray(), m_CommandCode);
}
