Microsoft Windows: Turn off multicast name resolution

##############################################################################
# OpenVAS Vulnerability Test
# $Id: win_dc_multicast_name_resolution.nasl 11337 2018-09-11 14:23:53Z emoss $
#
# Check value for Turn off multicast name resolution
#
# Authors:
# Emanuel Moss <[email protected]>
#
# Copyright:
# Copyright (c) 2018 Greenbone Networks GmbH, http://www.greenbone.net
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License version 2
# (or any later version), as published by the Free Software Foundation.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
###############################################################################

if(description)
{
  script_oid("1.3.6.1.4.1.25623.1.0.109323");
  script_version("$Revision: 11337 $");
  script_tag(name:"last_modification", value:"$Date: 2018-09-11 16:23:53 +0200 (Tue, 11 Sep 2018) $");
  script_tag(name:"creation_date", value:"2018-06-15 15:23:24 +0200 (Fri, 15 Jun 2018)");
  script_tag(name:"cvss_base", value:"0.0");
  script_tag(name:"cvss_base_vector", value:"AV:L/AC:H/Au:S/C:N/I:N/A:N");
  script_tag(name:"qod", value:"97");
  script_name('Microsoft Windows: Turn off multicast name resolution');
  script_category(ACT_GATHER_INFO);
  script_copyright("Copyright (c) 2018 Greenbone Networks GmbH");
  script_family("Policy");
  script_dependencies("smb_reg_service_pack.nasl");
  script_add_preference(name:"Value", type:"radio", value:"0;1");
  script_mandatory_keys("Compliance/Launch");
  script_tag(name:"summary", value:"This test checks the setting for policy
'Turn off multicast name resolution' on Windows hosts (at least Windows 7).

The setting controls the link local multicast name resolution (LLMNR).
LLMNR is a secondary name resolution protocol. With LLMNR, queries are sent
using multicast over a local network link on a single subnet from a client
computer to another client computer on the same subnet that also has LLMNR
enabled. LLMNR does not require a DNS server or DNS client configuration, and
provides name resolution in scenarios in which conventional DNS name resolution
is not possible.");
  exit(0);
}

include("smb_nt.inc");
include("policy_functions.inc");

if(!get_kb_item("SMB/WindowsVersion")){
  policy_logging(text:'Host is no Microsoft Windows System or it is not possible
to query the registry.');
  exit(0);
}

if(get_kb_item("SMB/WindowsVersion") < "6.1"){
  policy_logging(text:'Host is not at least a Microsoft Windows 7 system.
Older versions of Microsoft Windows are not supported any more.
Please update the system.');
  exit(0);
}

title = 'Turn off multicast name resolution';
fixtext = 'Set following UI path accordingly:
Computer Configuration/Administrative Templates/Network/DNS Client/' + title;
type = 'HKLM';
key = 'Software\\Policies\\Microsoft\\Windows NT\\DNSClient';
item = 'EnableMulticast';
default = script_get_preference('Value');
value = registry_get_dword(key:key, item:item, type:type);

if(value == ''){
  value = '1';
}

if(int(value) == int(default)){
  compliant = 'yes';
}else{
  compliant = 'no';
}

policy_logging(text:'"' + title + '" is set to: ' + value);
policy_add_oid();
policy_set_dval(dval:default);
policy_fixtext(fixtext:fixtext);
policy_control_name(title:title);
policy_set_kb(val:value);
policy_set_compliance(compliant:compliant);

exit(0);