xteld Service Detection

# SPDX-FileCopyrightText: 2005 Michel Arboi
# Some text descriptions might be excerpted from (a) referenced
# source(s), and are Copyright (C) by the respective right holder(s).
#
# SPDX-License-Identifier: GPL-2.0-only

if(description)
{
  script_oid("1.3.6.1.4.1.25623.1.0.11121");
  script_version("2023-08-01T13:29:10+0000");
  script_tag(name:"last_modification", value:"2023-08-01 13:29:10 +0000 (Tue, 01 Aug 2023)");
  script_tag(name:"creation_date", value:"2005-11-03 14:08:04 +0100 (Thu, 03 Nov 2005)");
  script_tag(name:"cvss_base_vector", value:"AV:N/AC:L/Au:N/C:N/I:N/A:N");
  script_tag(name:"cvss_base", value:"0.0");
  script_name("xteld Service Detection");
  script_category(ACT_GATHER_INFO);
  script_copyright("Copyright (C) 2005 Michel Arboi");
  script_family("Service detection");
  script_dependencies("find_service.nasl", "find_service1.nasl", "find_service2.nasl", "find_service3.nasl",
                      "find_service4.nasl", "find_service5.nasl", "find_service6.nasl", "find_service_spontaneous.nasl",
                      "find_service_3digits.nasl");
  script_require_ports(1313);

  script_tag(name:"summary", value:"Detection of an xteld service.");

  script_tag(name:"insight", value:"This service allows users to connect to the 'Teletel' network.
  Some of the servers are expensive. Note that by default, xteld forbids access to the most
  expensive services.");

  script_tag(name:"qod_type", value:"remote_banner");

  exit(0);
}

include("host_details.inc");
include("port_service_func.inc");
include("misc_func.inc");

port = 1313;
if(!get_port_state(port))
  exit(0);

# nb: No need to check e.g. HTTP services running on this port.
if(service_is_known(port:port))
  exit(0);

if(!soc = open_sock_tcp(port))
  exit(0);

vt_strings = get_vt_strings();
req = raw_string(6) + vt_strings["default"] + raw_string(0x82);
m = "";

send(socket:soc, data:req);

while(TRUE) {

  r = recv(socket:soc, length:1);
  if(strlen(r) == 0)
    break;

  len = ord(r);
  if(len == 130)
    break;

  r1 = recv(socket:soc, length:len);
  send(socket:soc, data:raw_string(0x83));
  r = recv(socket:soc, length:1);
  if(strlen(r) == 0)
    break;

  len = ord(r);
  if(len == 130)
    break;

  r2 = recv(socket:soc, length:len);
  send(socket:soc, data:raw_string(0x82));
  m = string(m, r1, " - ", r2, "\n");
}

close(soc);

if(strlen(m) > 0) {
  service_register(port:port, proto:"xtel");
  log_message(port:port, data:'Authorized services:\n' + m);
}

exit(0);