private bool HandleSocks5(Socket socket, IChannelDirectTcpip channel, TimeSpan timeout) { var authenticationMethodsCount = SocketAbstraction.ReadByte(socket, timeout); if (authenticationMethodsCount == -1) { // SOCKS client closed connection return(false); } var authenticationMethods = new byte[authenticationMethodsCount]; if (SocketAbstraction.Read(socket, authenticationMethods, 0, authenticationMethods.Length, timeout) == 0) { // SOCKS client closed connection return(false); } if (authenticationMethods.Min() == 0) { // no user authentication is one of the authentication methods supported // by the SOCKS client SocketAbstraction.Send(socket, new byte[] { 0x05, 0x00 }, 0, 2); } else { // the SOCKS client requires authentication, which we currently do not support SocketAbstraction.Send(socket, new byte[] { 0x05, 0xFF }, 0, 2); // we continue business as usual but expect the client to close the connection // so one of the subsequent reads should return -1 signaling that the client // has effectively closed the connection } var version = SocketAbstraction.ReadByte(socket, timeout); if (version == -1) { // SOCKS client closed connection return(false); } if (version != 5) { throw new ProxyException("SOCKS5: Version 5 is expected."); } var commandCode = SocketAbstraction.ReadByte(socket, timeout); if (commandCode == -1) { // SOCKS client closed connection return(false); } var reserved = SocketAbstraction.ReadByte(socket, timeout); if (reserved == -1) { // SOCKS client closed connection return(false); } if (reserved != 0) { throw new ProxyException("SOCKS5: 0 is expected for reserved byte."); } var addressType = SocketAbstraction.ReadByte(socket, timeout); if (addressType == -1) { // SOCKS client closed connection return(false); } IPAddress ipAddress; byte[] addressBuffer; switch (addressType) { case 0x01: { addressBuffer = new byte[4]; if (SocketAbstraction.Read(socket, addressBuffer, 0, 4, timeout) == 0) { // SOCKS client closed connection return(false); } ipAddress = new IPAddress(addressBuffer); } break; case 0x03: { var length = SocketAbstraction.ReadByte(socket, timeout); if (length == -1) { // SOCKS client closed connection return(false); } addressBuffer = new byte[length]; if (SocketAbstraction.Read(socket, addressBuffer, 0, addressBuffer.Length, timeout) == 0) { // SOCKS client closed connection return(false); } ipAddress = IPAddress.Parse(SshData.Ascii.GetString(addressBuffer, 0, addressBuffer.Length)); //var hostName = new Common.ASCIIEncoding().GetString(addressBuffer); //ipAddress = Dns.GetHostEntry(hostName).AddressList[0]; } break; case 0x04: { addressBuffer = new byte[16]; if (SocketAbstraction.Read(socket, addressBuffer, 0, 16, timeout) == 0) { // SOCKS client closed connection return(false); } ipAddress = new IPAddress(addressBuffer); } break; default: throw new ProxyException(string.Format("SOCKS5: Address type '{0}' is not supported.", addressType)); } var portBuffer = new byte[2]; if (SocketAbstraction.Read(socket, portBuffer, 0, portBuffer.Length, timeout) == 0) { // SOCKS client closed connection return(false); } var port = (uint)(portBuffer[0] * 256 + portBuffer[1]); var host = ipAddress.ToString(); RaiseRequestReceived(host, port); channel.Open(host, port, this, socket); SocketAbstraction.SendByte(socket, 0x05); if (channel.IsOpen) { SocketAbstraction.SendByte(socket, 0x00); } else { SocketAbstraction.SendByte(socket, 0x01); } // reserved SocketAbstraction.SendByte(socket, 0x00); if (ipAddress.AddressFamily == AddressFamily.InterNetwork) { SocketAbstraction.SendByte(socket, 0x01); } else if (ipAddress.AddressFamily == AddressFamily.InterNetworkV6) { SocketAbstraction.SendByte(socket, 0x04); } else { throw new NotSupportedException("Not supported address family."); } var addressBytes = ipAddress.GetAddressBytes(); SocketAbstraction.Send(socket, addressBytes, 0, addressBytes.Length); SocketAbstraction.Send(socket, portBuffer, 0, portBuffer.Length); return(true); }
private bool HandleSocks5(Socket socket, IChannelDirectTcpip channel, TimeSpan timeout) { var authenticationMethodsCount = SocketAbstraction.ReadByte(socket, timeout); if (authenticationMethodsCount == -1) { // SOCKS client closed connection return(false); } var authenticationMethods = new byte[authenticationMethodsCount]; if (SocketAbstraction.Read(socket, authenticationMethods, 0, authenticationMethods.Length, timeout) == 0) { // SOCKS client closed connection return(false); } if (authenticationMethods.Min() == 0) { // no user authentication is one of the authentication methods supported // by the SOCKS client SocketAbstraction.Send(socket, new byte[] { 0x05, 0x00 }, 0, 2); } else { // the SOCKS client requires authentication, which we currently do not support SocketAbstraction.Send(socket, new byte[] { 0x05, 0xFF }, 0, 2); // we continue business as usual but expect the client to close the connection // so one of the subsequent reads should return -1 signaling that the client // has effectively closed the connection } var version = SocketAbstraction.ReadByte(socket, timeout); if (version == -1) { // SOCKS client closed connection return(false); } if (version != 5) { throw new ProxyException("SOCKS5: Version 5 is expected."); } var commandCode = SocketAbstraction.ReadByte(socket, timeout); if (commandCode == -1) { // SOCKS client closed connection return(false); } var reserved = SocketAbstraction.ReadByte(socket, timeout); if (reserved == -1) { // SOCKS client closed connection return(false); } if (reserved != 0) { throw new ProxyException("SOCKS5: 0 is expected for reserved byte."); } var addressType = SocketAbstraction.ReadByte(socket, timeout); if (addressType == -1) { // SOCKS client closed connection return(false); } var host = GetSocks5Host(addressType, socket, timeout); if (host == null) { // SOCKS client closed connection return(false); } var portBuffer = new byte[2]; if (SocketAbstraction.Read(socket, portBuffer, 0, portBuffer.Length, timeout) == 0) { // SOCKS client closed connection return(false); } var port = (uint)(portBuffer[0] * 256 + portBuffer[1]); RaiseRequestReceived(host, port); channel.Open(host, port, this, socket); var socksReply = CreateSocks5Reply(channel.IsOpen); SocketAbstraction.Send(socket, socksReply, 0, socksReply.Length); return(true); }