Check for ident Service

# SPDX-FileCopyrightText: 2009 Greenbone AG
# 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("1.3.6.1.4.1.25623.1.0.113759");
  script_version("2023-07-28T16:09:07+0000");
  script_tag(name:"last_modification", value:"2023-07-28 16:09:07 +0000 (Fri, 28 Jul 2023)");
  script_tag(name:"creation_date", value:"2009-03-26 19:23:59 +0100 (Thu, 26 Mar 2009)");
  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_name("Check for ident Service");
  script_category(ACT_GATHER_INFO);
  script_copyright("Copyright (C) 2009 Greenbone AG");
  script_family("Service detection");
  script_dependencies("find_service.nasl");
  script_require_ports("Services/auth", 113);

  script_tag(name:"summary", value:"The remote host is running an ident daemon.

  The Ident Protocol is designed to work as a server daemon, on a user's
  computer, where it receives requests to a specified port, generally 113. The
  server will then send a specially designed response that identifies the
  username of the current user.");

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

  exit(0);
}

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

port = service_get_port( proto: "auth", default: 113 );
if( ! get_port_state( port ) ) exit( 0 );

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

data = strcat( port, ',', get_source_port( soc ) );
send( socket: soc, data:string( data, "\r\n" ) );
buf = recv_line( socket: soc, length: 1024 );

close( soc );

if( "ERROR" >< buf || data >< buf || "USERID" >< buf ) {
  service_register( port: port, proto: "auth" );
  set_kb_item( name: "ident/detected", value: TRUE );
  set_kb_item( name: "ident/port", value: port );
}

exit( 0 );