Exemplo n.º 1
0
        private void ProcessKEXINIT(DataFragment packet) {
            SSH2DataReader re = null;
            do {
                _serverKEXINITPayload = packet.ToNewArray();
                re = new SSH2DataReader(_serverKEXINITPayload);
                byte[] head = re.Read(17); //Type and cookie
                PacketType pt = (PacketType)head[0];

                if (pt == PacketType.SSH_MSG_KEXINIT)
                    break; //successfully exit
                else if (pt == PacketType.SSH_MSG_IGNORE || pt == PacketType.SSH_MSG_DEBUG) { //continue
                    packet = _connection.ReceivePacket();
                }
                else
                    throw new SSHException(String.Format("Server response is not SSH_MSG_KEXINIT but {0}", head[0]));
            } while (true);

            Encoding enc = Encoding.ASCII;

            string kex = enc.GetString(re.ReadString());
            _cInfo._supportedKEXAlgorithms = kex;
            _cInfo._kexAlgorithm = DecideKexAlgorithm(kex);

            string host_key = enc.GetString(re.ReadString());
            _cInfo._supportedHostKeyAlgorithms = host_key;
            _cInfo._algorithmForHostKeyVerification = DecideHostKeyAlgorithm(host_key);

            string enc_cs = enc.GetString(re.ReadString());
            _cInfo._supportedCipherAlgorithms = enc_cs;
            _cInfo._algorithmForTransmittion = DecideCipherAlgorithm(enc_cs);

            string enc_sc = enc.GetString(re.ReadString());
            _cInfo._algorithmForReception = DecideCipherAlgorithm(enc_sc);

            string mac_cs = enc.GetString(re.ReadString());
            CheckAlgorithmSupport("mac", mac_cs, "hmac-sha1");

            string mac_sc = enc.GetString(re.ReadString());
            CheckAlgorithmSupport("mac", mac_sc, "hmac-sha1");

            string comp_cs = enc.GetString(re.ReadString());
            CheckAlgorithmSupport("compression", comp_cs, "none");
            string comp_sc = enc.GetString(re.ReadString());
            CheckAlgorithmSupport("compression", comp_sc, "none");

            string lang_cs = enc.GetString(re.ReadString());
            string lang_sc = enc.GetString(re.ReadString());
            bool flag = re.ReadBool();
            int reserved = re.ReadInt32();
            Debug.Assert(re.Rest == 0);

            if (_connection.IsEventTracerAvailable) {
                StringBuilder bld = new StringBuilder();
                bld.Append("kex_algorithm=");
                bld.Append(kex);
                bld.Append("; server_host_key_algorithms=");
                bld.Append(host_key);
                bld.Append("; encryption_algorithms_client_to_server=");
                bld.Append(enc_cs);
                bld.Append("; encryption_algorithms_server_to_client=");
                bld.Append(enc_sc);
                bld.Append("; mac_algorithms_client_to_server=");
                bld.Append(mac_cs);
                bld.Append("; mac_algorithms_server_to_client=");
                bld.Append(mac_sc);
                bld.Append("; comression_algorithms_client_to_server=");
                bld.Append(comp_cs);
                bld.Append("; comression_algorithms_server_to_client=");
                bld.Append(comp_sc);
                TraceReceptionNegotiation(PacketType.SSH_MSG_KEXINIT, bld.ToString());
            }

            if (flag)
                throw new SSHException("Algorithm negotiation failed");
        }