SSL/TLS: IRC 'STARTTLS' Command Detection

# Copyright (C) 2017 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("1.3.6.1.4.1.25623.1.0.108072");
  script_version("2022-06-01T21:00:42+0000");
  script_tag(name:"last_modification", value:"2022-06-01 21:00:42 +0000 (Wed, 01 Jun 2022)");
  script_tag(name:"creation_date", value:"2017-02-07 11:18:02 +0100 (Tue, 07 Feb 2017)");
  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: IRC 'STARTTLS' Command Detection");

  script_category(ACT_GATHER_INFO);
  script_family("SSL and TLS");
  script_copyright("Copyright (C) 2017 Greenbone Networks GmbH");
  script_dependencies("find_service.nasl", "find_service2.nasl");
  script_require_ports("Services/irc", 6667);

  script_add_preference(name:"Run routine", type:"checkbox", value:"no", id:1);

  script_tag(name:"summary", value:"Checks if the remote IRC server supports SSL/TLS with the 'STARTTLS' command.

  Note: This script is not running by default as most IRC servers are throttling too many
  connections and rejecting further requests. If you want to test your IRC server please
  exclude the IP of the scanner from this throttling mechanism.");

  script_xref(name:"URL", value:"https://ircv3.net/specs/extensions/tls-3.1.html");

  exit(0);
}

include("port_service_func.inc");

run_script = script_get_preference( "Run routine" );
if( "no" >< run_script ) exit( 0 );

port = service_get_port( default:6667, proto:"irc" );


if( get_port_transport( port ) > ENCAPS_IP ) exit( 0 );

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

send( socket:soc, data:'STARTTLS\r\n' );

while( buf = recv_line( socket:soc, length:2048 ) ) {
  if( ":STARTTLS successful" >< buf ) {
    set_kb_item( name:"irc/" + port + "/starttls", value:TRUE );
    set_kb_item( name:"starttls_typ/" + port, value:"irc" );
    log_message( port:port, data:"The remote IRC server supports SSL/TLS with the 'STARTTLS' command." );
    close( soc );
    exit( 0 );
  }
}

close( soc );
exit( 0 );