Inter-Asterisk eXchange Protocol Detection

# SPDX-FileCopyrightText: 2006 Ferdy Riphagen
# 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("1.3.6.1.4.1.25623.1.0.20834");
  script_tag(name:"cvss_base_vector", value:"AV:N/AC:L/Au:N/C:N/I:N/A:N");
  script_version("2023-08-01T13:29:10+0000");
  script_tag(name:"last_modification", value:"2023-08-01 13:29:10 +0000 (Tue, 01 Aug 2023)");
  script_tag(name:"creation_date", value:"2006-03-26 17:55:15 +0200 (Sun, 26 Mar 2006)");
  script_tag(name:"cvss_base", value:"0.0");

  script_name("Inter-Asterisk eXchange Protocol Detection");

  script_category(ACT_GATHER_INFO);
  script_tag(name:"qod_type", value:"remote_banner");
  script_family("Service detection");
  script_copyright("Copyright (C) 2006 Ferdy Riphagen");
  script_require_udp_ports(4569);

  script_tag(name:"solution", value:"If possible, filter incoming connections to the port so that it is used by
trusted sources only.");

  script_tag(name:"summary", value:"The remote system is running a server that speaks the Inter-Asterisk eXchange
Protocol.

Description :

The Inter-Asterisk eXchange protocol (IAX2) is used by the Asterisk PBX Server and other IP Telephony
clients/servers to enable voice communication between them.");

  script_xref(name:"URL", value:"http://en.wikipedia.org/wiki/IAX");

  exit(0);
}

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

port = 4569;
if (!get_udp_port_state(port)) exit(0);

# TBD: Really? Open the socket but don't check the state of it.
soc = open_sock_udp(port);

# Generate the 'IAX2' poke packet.
poke_msg = raw_string(0x80, 0x00,             # IAX2 Full Packet Type
                      0x00, 0x00,             # Destination Call
                      0x00, 0x00, 0x00, 0x00, # Timestamp
                      0x00,                   # Outbound Seq No
                      0x00,                   # Inbound Seq No
                      0x06,                   # IAX Type
                      0x1E);                  # IAX2 Poke Command

# Send the poke request.
send(socket:soc, data:poke_msg);

recv = recv(socket:soc, length:128);
if (recv == NULL) exit(0);

if (strlen(recv) != 12) exit(0);

if (ord(recv[10]) == 6 &&  # IAX Type
   (ord(recv[11]) == 3 ||  # IAX PONG
    ord(recv[11]) == 4)) { # IAX ACK
 log_message(port);
 service_register(ipproto:"udp", proto:"iax2", port:port);
 exit(0);
}

exit(0);