re2o/freeradius_utils/auth.py

# -*- mode: python; coding: utf-8 -*-
# Re2o est un logiciel d'administration développé initiallement au Rézo Metz. Il
# se veut agnostique au réseau considéré, de manière à être installable en
# quelques clics.
#
# Copyirght © 2017  Daniel Stan
# Copyright © 2017  Gabriel Détraz
# Copyright © 2017  Lara Kermarec
# Copyright © 2017  Augustin Lemesle
# Copyright © 2020  Corentin Canebier
#
# 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 Street, Fifth Floor, Boston, MA 02110-1301 USA.

"""
Python backend for freeradius.

This file contains definition of some functions called by freeradius backend
during auth for wifi, wired device and nas.

Other examples can be found here :
https://github.com/FreeRADIUS/freeradius-server/blob/master/src/modules/rlm_python/

Inspired by Daniel Stan in Crans
"""

from configparser import ConfigParser

from re2oapi import Re2oAPIClient

import sys
import os
import subprocess
import logging
import traceback
import radiusd
from requests import HTTPError
import urllib.parse

path = (os.path.dirname(os.path.abspath(__file__)))

config = ConfigParser()
config.read(path+'/config.ini')

api_hostname = config.get('Re2o', 'hostname')
api_password = config.get('Re2o', 'password')
api_username = config.get('Re2o', 'username')

global api_client
api_client = Re2oAPIClient(
    api_hostname, api_username, api_password, use_tls=True)


class RadiusdHandler(logging.Handler):
    """Handler de logs pour freeradius"""

    def emit(self, record):
        """Process un message de log, en convertissant les niveaux"""
        if record.levelno >= logging.WARN:
            rad_sig = radiusd.L_ERR
        elif record.levelno >= logging.INFO:
            rad_sig = radiusd.L_INFO
        else:
            rad_sig = radiusd.L_DBG
        radiusd.radlog(rad_sig, str(record.msg))


# Initialisation d'un logger (pour logguer unifi  )
logger = logging.getLogger("auth.py")
logger.setLevel(logging.DEBUG)
formatter = logging.Formatter("%(name)s: [%(levelname)s] %(message)s")
handler = RadiusdHandler()
handler.setFormatter(formatter)
logger.addHandler(handler)


def radius_event(fun):
    """Décorateur pour les fonctions d'interfaces avec radius.
    Une telle fonction prend un uniquement argument, qui est une liste de
    tuples (clé, valeur) et renvoie un triplet dont les composantes sont :
     * le code de retour (voir radiusd.RLM_MODULE_* )
     * un tuple de couples (clé, valeur) pour les valeurs de réponse (accès ok
       et autres trucs du genre)
     * un tuple de couples (clé, valeur) pour les valeurs internes à mettre à
       jour (mot de passe par exemple)

    On se contente avec ce décorateur (pour l'instant) de convertir la liste de
    tuples en entrée en un dictionnaire."""

    def new_f(auth_data):
        """ The function transforming the tuples as dict """
        if isinstance(auth_data, dict):
            data = auth_data
        else:
            data = dict()
            for (key, value) in auth_data or []:
                # Beware: les valeurs scalaires sont entre guillemets
                # Ex: Calling-Station-Id: "une_adresse_mac"
                data[key] = value.replace('"', "")
        try:
            # TODO s'assurer ici que les tuples renvoy  s sont bien des
            # (str,str) : rlm_python ne dig  re PAS les unicodes
            return fun(data)
        except Exception as err:
            exc_type, exc_instance, exc_traceback = sys.exc_info()
            formatted_traceback = "".join(traceback.format_tb(exc_traceback))
            logger.error("Failed %r on data %r" % (err, auth_data))
            logger.error("Function %r, Traceback : %r" %
                         (fun, formatted_traceback))
            return radiusd.RLM_MODULE_FAIL

    return new_f


@radius_event
def instantiate(*_):
    """Usefull for instantiate ldap connexions otherwise,
    do nothing"""
    logger.info("Instantiation")


@radius_event
def authorize(data):
    # Pour les requetes proxifiees, on split
    nas = data.get("NAS-IP-Address", data.get("NAS-Identifier", None))
    username = data.get("User-Name", "")
    username = username.split("@", 1)[0]
    mac = data.get("Calling-Station-Id", "")

    data_from_api = api_client.view(
        "radius/authorize/{0}/{1}/{2}".format(
            urllib.parse.quote(nas or "None", safe=""),
            urllib.parse.quote(username or "None", safe=""),
            urllib.parse.quote(mac or "None", safe="")
        ))

    nas_type = data_from_api["nas"]
    user = data_from_api["user"]
    user_interface = data_from_api["user_interface"]

    if nas_type and nas_type["port_access_mode"] == "802.1X":
        result, log, password = check_user_machine_and_register(
            nas_type, user, user_interface, nas, username, mac)
        logger.info(log.encode("utf-8"))
        logger.info(username.encode("utf-8"))

        if not result:
            return radiusd.RLM_MODULE_REJECT
        else:
            return (
                radiusd.RLM_MODULE_UPDATED,
                (),
                ((str("NT-Password"), str(password)),),
            )

    else:
        return (radiusd.RLM_MODULE_UPDATED, (), (("Auth-Type", "Accept"),))


@radius_event
def post_auth(data):
    """ Function called after the user is authenticated
    """

    nas = data.get("NAS-IP-Address", data.get("NAS-Identifier", None))
    nas_port = data.get("NAS-Port-Id", data.get("NAS-Port", None))
    mac = data.get("Calling-Station-Id", None)

    data_from_api = api_client.view(
        "radius/post_auth/{0}/{1}/{2}".format(
            urllib.parse.quote(nas or "None", safe=""),
            urllib.parse.quote(nas_port or "None", safe=""),
            urllib.parse.quote(mac or "None", safe="")
        ))

    nas_type = data_from_api["nas"]
    port = data_from_api["port"]
    switch = data_from_api["switch"]

    if not nas_type:
        logger.info("Proxified request, nas unknown")
        return radiusd.RLM_MODULE_OK

    # If it is a switch
    if switch:
        sw_name = switch["name"] or "?"
        room = "Unknown port"
        if port:
            room = port["room"] or "Unknown room"

        out = decide_vlan_switch(data_from_api, mac, nas_port)
        reason, vlan_id, decision, attributes = out

        if decision:
            log_message = "(wired) %s -> %s [%s%s]" % (
                sw_name + ":" + nas_port + "/" + str(room),
                mac,
                vlan_id,
                (reason and ": " + reason),
            )
            logger.info(log_message)

            # Wired connexion
            return (
                radiusd.RLM_MODULE_UPDATED,
                (
                    ("Tunnel-Type", "VLAN"),
                    ("Tunnel-Medium-Type", "IEEE-802"),
                    ("Tunnel-Private-Group-Id", "%d" % int(vlan_id)),
                )
                + tuple(attributes),
                (),
            )
        else:
            log_message = "(wired) %s -> %s [Reject %s]" % (
                sw_name + ":" + nas_port + "/" + str(room),
                mac,
                (reason and ": " + reason),
            )
            logger.info(log_message)

            return (radiusd.RLM_MODULE_REJECT, tuple(attributes), ())

    else:
        return radiusd.RLM_MODULE_OK


def check_user_machine_and_register(nas_type, user, user_interface, nas_id, username, mac_address):
    """Check if username and mac are registered. Register it if unknown.
    Return the user ntlm password if everything is ok.
    Used for 802.1X auth"""
    if not user:
        return (False, "User unknown", "")
    if not user["access"]:
        return (False, "Invalid connexion (non-contributing user)", "")
    if user_interface:
        if user_interface["user_pk"] != user["pk"]:
            return (
                False,
                "Mac address registered on another user account",
                "",
            )
        elif not user_interface["active"]:
            return (False, "Interface/Machine disabled", "")
        elif not user_interface["ipv4"]:
            try:
                api_client.view(
                    "radius/assign_ip/{0}".format(
                        urllib.parse.quote(mac_address or "None", safe="")
                    ))
                return (True, "Ok, new ipv4 assignement...", user.get("pwd_ntlm", ""))
            except HTTPError as err:
                return (False, "Error during ip assignement %s" % err.response.text, "")
        else:
            return (True, "Access ok", user.get("pwd_ntlm", ""))
    elif nas_type:
        if nas_type["autocapture_mac"]:
            try:
                api_client.view(
                    "radius/autoregister/{0}/{1}/{2}".format(
                        urllib.parse.quote(nas_id or "None", safe=""),
                        urllib.parse.quote(username or "None", safe=""),
                        urllib.parse.quote(mac_address or "None", safe="")
                    ))
                return (True, "Access Ok, Registering mac...", user["pwd_ntlm"])
            except HTTPError as err:
                return (False, "Error during mac register %s" % err.response.text, "")
            return (False, "L'auto capture est désactivée", "")
        else:
            return (False, "Unknown interface/machine", "")
    else:
        return (False, "Unknown interface/machine", "")


def set_radius_attributes_values(attributes, values):
    return (
        (str(attribute["attribute"]), str(attribute["value"] % values))
        for attribute in attributes
    )


def decide_vlan_switch(data_from_api, user_mac, nas_port):
    """Function for selecting vlan for a switch with wired mac auth radius.
    Several modes are available :
        - all modes:
           - unknown NAS : VLAN_OK,
           - unknown port : Decision set in Re2o RadiusOption
        - No radius on this port : VLAN_OK
        - force : returns vlan provided by the database
        - mode strict:
            - no room : Decision set in Re2o RadiusOption,
            - no user in this room : Reject,
            - user of this room is banned or disable : Reject,
            - user of this room non-contributor and not whitelisted: 
            Decision set in Re2o RadiusOption
        - mode common :
            - mac-address already registered:
                - related user non contributor / interface disabled:
                Decision set in Re2o RadiusOption
                - related user is banned:
                Decision set in Re2o RadiusOption
                - user contributing : VLAN_OK (can assign ipv4 if needed)
            - unknown interface :
                - register mac disabled : Decision set in Re2o RadiusOption
                - register mac enabled : redirect to webauth
    Returns:
        tuple with :
            - Switch name (str)
            - Room (str)
            - Reason of the decision (str)
            - vlan_id (int)
            - decision (bool)
            - Other Attributs (attribut:str, operator:str, value:str)
    """

    nas_type = data_from_api["nas"]
    room_users = data_from_api["room_users"]
    port = data_from_api["port"]
    port_profile = data_from_api["port_profile"]
    switch = data_from_api["switch"]
    user_interface = data_from_api["user_interface"]
    radius_option = data_from_api["radius_option"]
    EMAIL_STATE_UNVERIFIED = data_from_api["EMAIL_STATE_UNVERIFIED"]
    RADIUS_OPTION_REJECT = data_from_api["RADIUS_OPTION_REJECT"]
    USER_STATE_ACTIVE = data_from_api["USER_STATE_ACTIVE"]

    attributes_kwargs = {
        "client_mac": str(user_mac),
        "switch_port": str(nas_port.split(".")[0].split("/")[-1][-2:]),
        "switch_ip": str(switch["ipv4"])
    }

    # Get port from switch and port number
    extra_log = ""

    # If the port is unknwon, go to default vlan
    # We don't have enought information to make a better decision
    if not port or not port_profile:
        return (
            "Unknown port",
            radius_option["unknown_port_vlan"] and radius_option["unknown_port_vlan"]["vlan_id"] or None,
            radius_option["unknown_port"] != RADIUS_OPTION_REJECT,
            set_radius_attributes_values(
                radius_option["unknown_port_attributes"], attributes_kwargs),
        )

    # If a vlan is precised in port config, we use it
    if port_profile["vlan_untagged"]:
        DECISION_VLAN = int(port_profile["vlan_untagged"]["vlan_id"])
        extra_log = "Force sur vlan " + str(DECISION_VLAN)
        attributes = ()
    else:
        DECISION_VLAN = radius_option["vlan_decision_ok"]["vlan_id"]
        attributes = set_radius_attributes_values(
            radius_option["ok_attributes"], attributes_kwargs)

    # If the port is disabled in re2o, REJECT
    if not port["state"]:
        return ("Port disabled", None, False, ())

    # If radius is disabled, decision is OK
    if port_profile["radius_type"] == "NO":
        return (
            "No Radius auth enabled on this port" + extra_log,
            DECISION_VLAN,
            True,
            attributes,
        )

    # If 802.1X is enabled, people has been previously accepted.
    # Go to the decision vlan
    if (nas_type["port_access_mode"], port_profile["radius_type"]) == ("802.1X", "802.1X"):
        return (
            "Accept authentication 802.1X",
            DECISION_VLAN,
            True,
            attributes,
        )

    # Otherwise, we are in mac radius.
    # If strict mode is enabled, we check every user related with this port. If
    # one user or more is not enabled, we reject to prevent from sharing or
    # spoofing mac.
    if port_profile["radius_mode"] == "STRICT":
        if not port["room"]:
            return (
                "Unkwown room",
                radius_option["unknown_room_vlan"] and radius_option["unknown_room_vlan"]["vlan_id"] or None,
                radius_option["unknown_room"] != RADIUS_OPTION_REJECT,
                set_radius_attributes_values(
                    radius_option["unknown_room_attributes"], attributes_kwargs),
            )

        if not room_users:
            return (
                "Non-contributing room",
                radius_option["non_member_vlan"] and radius_option["non_member_vlan"]["vlan_id"] or None,
                radius_option["non_member"] != RADIUS_OPTION_REJECT,
                set_radius_attributes_values(
                    radius_option["non_member_attributes"], attributes_kwargs),
            )

        all_user_ban = True
        at_least_one_active_user = False

        for user in room_users:
            if not user["is_ban"] and user["state"] == USER_STATE_ACTIVE:
                all_user_ban = False
            if user["email_state"] != EMAIL_STATE_UNVERIFIED and (user["is_connected"] or user["is_whitelisted"]):
                at_least_one_active_user = True

        if all_user_ban:
            return (
                "User is banned or disabled",
                radius_option["banned_vlan"] and radius_option["banned_vlan"]["vlan_id"] or None,
                radius_option["banned"] != RADIUS_OPTION_REJECT,
                set_radius_attributes_values(
                    radius_option["banned_attributes"], attributes_kwargs),
            )
        if not at_least_one_active_user:
            return (
                "Non-contributing member or unconfirmed mail",
                radius_option["non_member_vlan"] and radius_option["non_member_vlan"]["vlan_id"] or None,
                radius_option["non_member"] != RADIUS_OPTION_REJECT,
                set_radius_attributes_values(
                    radius_option["non_member_attributes"], attributes_kwargs),
            )
        # else: user OK, so we check MAC now

    # If we are authenticating with mac, we look for the interfaces and its mac address
    if port_profile["radius_mode"] == "COMMON" or port_profile["radius_mode"] == "STRICT":
        # If mac is unknown,
        if not user_interface:
            # We try to register mac, if autocapture is enabled
            # Final decision depend on RADIUSOption set in re2o
            if nas_type["autocapture_mac"]:
                return (
                    "Unknown mac/interface",
                    radius_option["unknown_machine_vlan"] and radius_option["unknown_machine_vlan"]["vlan_id"] or None,
                    radius_option["unknown_machine"] != RADIUS_OPTION_REJECT,
                    set_radius_attributes_values(
                        radius_option["unknown_machine_attributes"], attributes_kwargs),
                )
            # Otherwise, if autocapture mac is not enabled,
            else:
                return (
                    "Unknown mac/interface",
                    radius_option["unknown_machine_vlan"] and radius_option["unknown_machine_vlan"]["vlan_id"] or None,
                    radius_option["unknown_machine"] != RADIUS_OPTION_REJECT,
                    set_radius_attributes_values(
                        radius_option["unknown_machine_attributes"], attributes_kwargs),
                )

        # Mac/Interface is found, check if related user is contributing and ok
        # If needed, set ipv4 to it
        else:
            if user_interface["is_ban"]:
                return (
                    "Banned user",
                    radius_option["banned_vlan"] and radius_option["banned_vlan"]["vlan_id"] or None,
                    radius_option["banned"] != RADIUS_OPTION_REJECT,
                    set_radius_attributes_values(
                        radius_option["banned_attributes"], attributes_kwargs),
                )
            if not user_interface["active"]:
                return (
                    "Disabled interface / non-contributing member",
                    radius_option["non_member_vlan"] and radius_option["non_member_vlan"]["vlan_id"] or None,
                    radius_option["non_member"] != RADIUS_OPTION_REJECT,
                    set_radius_attributes_values(
                        radius_option["non_member_attributes"], attributes_kwargs),
                )
            # If settings is set to related interface vlan policy based on interface type:
            if radius_option["radius_general_policy"] == "MACHINE":
                DECISION_VLAN = user_interface["vlan_id"]
            if not user_interface["ipv4"]:
                try:
                    api_client.view(
                        "radius/assign_ip/{0}".format(
                            urllib.parse.quote(user_mac or "None", safe="")
                        ))
                    return (
                        "Ok, assigning new ipv4" + extra_log,
                        DECISION_VLAN,
                        True,
                        attributes,
                    )
                except HTTPError as err:
                    return (
                        "Error during ip assignement %s" % err.response.text + extra_log,
                        DECISION_VLAN,
                        True,
                        attributes,
                    )

            else:
                return (
                    "Interface OK" + extra_log,
                    DECISION_VLAN,
                    True,
                    attributes,
                )