Microsoft Windows: Do not display last user name

##############################################################################
# OpenVAS Vulnerability Test
# $Id: win_il_display_last_user.nasl 11532 2018-09-21 19:07:30Z cfischer $
#
# Check value for Interactive logon: Do not display last user name
#
# 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("1.3.6.1.4.1.25623.1.0.109161");
  script_version("$Revision: 11532 $");
  script_tag(name:"last_modification", value:"$Date: 2018-09-21 21:07:30 +0200 (Fri, 21 Sep 2018) $");
  script_tag(name:"creation_date", value:"2018-06-01 15:03:15 +0200 (Fri, 01 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: Do not display last user name');
  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:"1;0");
  script_mandatory_keys("Compliance/Launch");
  script_tag(name:"summary", value:"This test checks the setting for policy
'Interactive logon: Do not display last user name' on Windows hosts (at least
Windows 7). With Windows 10, this policy setting was renamed to 'Interactive
logon: Don't display last signed-in'.

If enabled, the full name of the last user to successfully log on is not
displayed, nor is the user's logon tile displayed. Additionally, if the Switch
user feature is used, the full name and logon tile are not displayed. The logon
screen requests a qualified domain account name (or local user name) and password.");
  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 Windows are not supported any more. Please update the
Operating System.');
  exit(0);
}

type = 'HKLM';
key = 'Software\\Microsoft\\Windows\\CurrentVersion\\Policies\\System';
item = 'DontDisplayLastUserName';
title = 'Interactive logon: Do not display last user name';
fixtext = 'Set following UI path accordingly:
Computer Configuration/Windows Settings/Security Settings/Local Policies/Security Options/' + title;
default = script_get_preference('Value');
value = registry_get_dword(key:key, item:item, type:type);
value = chomp(value);

if( value == ''){
  value = '0';
}

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);