re2o/freeradius_utils/auth.py

# -*- mode: python; coding: utf-8 -*-
# Re2o est un logiciel d'administration développé initiallement au rezometz. 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
"""

import logging
import os
import sys
import traceback

import radiusd  # Magic module freeradius (radiusd.py is dummy)
from django.core.wsgi import get_wsgi_application
from django.db.models import Q

proj_path = "/var/www/re2o/"
# This is so Django knows where to find stuff.
os.environ.setdefault("DJANGO_SETTINGS_MODULE", "re2o.settings")
sys.path.append(proj_path)

# This is so my local_settings.py gets loaded.
os.chdir(proj_path)

# This is so models get loaded.
application = get_wsgi_application()

from machines.models import Domain, Interface, IpList, Nas
from preferences.models import RadiusOption
from topologie.models import Port, Switch
from users.models import User

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, record.msg.encode("utf-8"))


# Init for logging
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")
    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)


@radius_event
def authorize(data):
    """Here, we test if the Nas is known.
    - If the nas is unknown, we assume that it is a 802.1X request,
    - If the nas is known, we apply the 802.1X if enabled,
    - It the nas is known AND nas auth is enabled with mac address, returns
    accept here"""
    # For proxified request, split
    nas = data.get("NAS-IP-Address", data.get("NAS-Identifier", None))
    nas_instance = find_nas_from_request(nas)
    # For none proxified requests
    nas_type = None
    if nas_instance:
        nas_type = Nas.objects.filter(nas_type=nas_instance.machine_type).first()
    if not nas_type or nas_type.port_access_mode == "802.1X":
        user = data.get("User-Name", "")
        user = user.split("@", 1)[0]
        mac = data.get("Calling-Station-Id", "")
        result, log, password = check_user_machine_and_register(nas_type, user, mac)
        logger.info(str(log))
        logger.info(str(user))

        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_instance = find_nas_from_request(nas)
    # All non proxified requests
    if not nas_instance:
        logger.info("Proxified request, nas unknown")
        return radiusd.RLM_MODULE_OK
    nas_type = Nas.objects.filter(nas_type=nas_instance.machine_type).first()
    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 + ":" + 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 = "(fil) %s -> %s [Reject %s]" % (
                sw_name + ":" + 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):
    """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"]:
            # interface.assign_ipv4()
            return (True, "Ok, new ipv4 assignement...", user.get("pwd_ntlm", ""))
        else:
            return (True, "Access ok", user.get("pwd_ntlm", ""))
    elif nas_type:
        if nas_type["autocapture_mac"]:
            # result, reason = user.autoregister_machine(mac_address, nas_type)
            # if result:
            #     return (True, "Access Ok, Registering mac...", user.pwd_ntlm)
            # else:
            #     return (False, "Error during mac register %s" % reason, "")
            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 NAS is unknown, go to default vlan
    if not nas_machine:
        return (
            "?",
            "Unknown room",
            "Unknown NAS",
            RadiusOption.get_cached_value("vlan_decision_ok").vlan_id,
            True,
            RadiusOption.get_attributes("ok_attributes", attributes_kwargs),
        )

    sw_name = str(getattr(nas_machine, "short_name", str(nas_machine)))

    switch = Switch.objects.filter(machine_ptr=nas_machine).first()
    attributes_kwargs["switch_ip"] = str(switch.ipv4)
    port = Port.objects.filter(switch=switch, port=port_number).first()

    # 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),
        )

    # Retrieve port profile
    port_profile = port.get_port_profile

    # 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
            elif 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"]:
                # interface.assign_ipv4()
                return (
                    "Ok, assigning new ipv4" + extra_log,
                    DECISION_VLAN,
                    True,
                    attributes,
                )
            else:
                return (
                    "Interface OK" + extra_log,
                    DECISION_VLAN,
                    True,
                    attributes,
                )