SSL/TLS: Client Certificate Required (HTTP)

# Copyright (C) 2021 Greenbone Networks GmbH
# 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-or-later
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
#
# 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("1.3.6.1.4.1.25623.1.0.147115");
  script_version("2021-12-06T13:33:44+0000");
  script_tag(name:"last_modification", value:"2021-12-06 13:33:44 +0000 (Mon, 06 Dec 2021)");
  script_tag(name:"creation_date", value:"2021-11-08 02:32:25 +0000 (Mon, 08 Nov 2021)");
  script_tag(name:"cvss_base", value:"0.0");
  script_tag(name:"cvss_base_vector", value:"AV:N/AC:L/Au:N/C:N/I:N/A:N");

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

  script_name("SSL/TLS: Client Certificate Required (HTTP)");

  script_category(ACT_GATHER_INFO);

  script_copyright("Copyright (C) 2021 Greenbone Networks GmbH");
  script_family("SSL and TLS");
  script_dependencies("find_service.nasl", "httpver.nasl", "global_settings.nasl");
  script_require_ports("Services/www", 443);
  script_exclude_keys("Settings/disable_cgi_scanning");

  script_tag(name:"summary", value:"The remote HTTP service requires an SSL/TLS client
  certificate.");

  script_tag(name:"vuldetect", value:"Sends a HTTP request and checks the response.");

  exit(0);
}

include("host_details.inc");
include("http_func.inc");
include("http_keepalive.inc");
include("port_service_func.inc");

port = http_get_port(default: 443);

res = http_get_cache(port: port, item: "/");

if ((res =~ "^HTTP/1\.[01] 400" && ("<title>400 No required SSL certificate was sent</title>" >< res || "<center>No required SSL certificate was sent</center>" >< res)) # nginx
   ) {
  report = 'The remote HTTP service requires an SSL/TLS client certificate.\n\nResult:\n\n' + res;
  log_message(port: port, data: report);
  exit(0);
}

exit(0);