Introduction
This solution employs a router/server computer with two network interfaces, one is a network uplink, the other connects to the wifi routers with their respective supplicants.
Users authenticate using a username and password, and verify the identity of the RADIUS server using a certificate presented by the server (see more information under supplicant configuration).
As mentioned in '@@@', the NASes available do not support sending RADIUS accounting packets, they are only able to authenticate users against the response from a RADIUS server. This solution uses 802.1X to authenticate users and let them into the wireless network, and then Shorewall to perform the logging/accounting work. FreeRADIUS logs the MAC address of all devices that connect along with the username they authenticated as, this information can be used to match information in Shorewall's logs to a user session. For improved security the firewall policy will be to disallow all connections except those originating from known IP addresses of known wifi clients. A script, shwl_add.sh, gets run by FreeRADIUS upon successful authentication of a supplicant, which runs an ARP scan to find the IP address of the device with the MAC address specified by FreeRADIUS, it then adds the IP address to shorewall's "whitelist", logs the event along with some useful information to a MySQL database and writes the current timestamp to a text file. In Access-Accept packets the Session-Timeout and Termination-Action attributes are sent, informing the NAS that after the specified amount of time the supplicant needs to repeat the authentication process or be disconnected. When the supplicant repeats authentication the mentioned script detects that the supplicant is already known and simply logs the event to MySQL and updates the timestamp in the text file. Another script, shwl_del.sh, is run by crontab at a regular interval, which goes through all the IP addresses present in shorewall's "whitelist" and checks the timestamp of the corresponding supplicant's last authentication to FreeRADIUS in the corresponding text file. If more than the specified amount of time has passed, this script assumes that the supplicant has disconnected from the wifi network and removes its IP from shorewall's "whitelist", logs the event to MySQL, and deletes the related text files.
A python script, script_launcher.py, serves as an intermediary that is launched by FreeRADIUS using its Rlm_python module and in turn launches shwl_add.sh.
The database backend containing user credentials for FreeRADIUS is MySQL. Adding/deleting users can be accomplished by SQL queries which can be included in site specific custom user management scripts or as hooks to the standard 'adduser' and 'deluser' utilities (out of the scope of this guide). Updating of passwords is accomplished by a script, pam_to_mysql_update.sh, that gets run by the libpam-script PAM module during PAM stack execution, and updates the password in the MySQL database according to the same password the user chose for their system user account. An entry with the username field already filled and matching the system user account username needs to be already present in the MySQL database. Commands that expire or disable a user's system user account (or password) without deleting it (such as passwd -l) will not cause the credentials in the MySQL database to be disabled, thus it is necessary to take care (perhaps with a site specific lock user script) to also invalidate the same.
Shorewall dynamic zones are used to achieve the dynamic change of firewall rules set for the IP addresses added/removed to the "whitelist". The rules for the normal zone concerning the network connecting to the NASes/supplicants disallows all connections, except those needed for the RADIUS conversation between the NASes and FreeRADIUS. A dynamic zone is declared under the normal zone, whose rules allow network access, with logging. The 'shorewall add <dynamic_zone_name> <ip_address>' and 'shorewall delete <dynamic_zone_name> <ip_address>' commands can then be used by the shwl_*.sh scripts to change the rules applicable for the specified source IP address.
Sudo is installed and configured as it is required for some of the mentioned scripts to run commands as root or as a different user.
A package containing the mentiond scripts, as well as the empty MySQL schema for the database used by some of them, is attached to this wiki page.
Installation
Replication of production setup
Here, we replicate the relevant configuration already present on server.lastschl.av as a starting point. The test virtual machine will have two network interfaces, one serving as uplink on a 192.168.10.0/24 network (IP 192.168.10.52), and one to connect to the wifi routers/clients on a 192.168.9.0/24 network (IP 192.168.9.1). The FQDN will be server.test.av.
Base virtual machine preparation
Imported Last School's Debian9 VM template "Debian9-base.ova" into Virtual Box as Debian9-base_8021x, re-initializing all MAC addresses. The description for this virtual machine template is:
Debian 9 amd64 installation - Hostname: debian9-base - User accounts (username password): ls last root last - Partitioning: --- Physical: ------ 1GB RAID boot flag ------ 29GB RAID --- RAID: ------ md0: ext3 /boot ------ md1: LVM - part of volume group debian9-base --- LVM (VG/LV): ------ debian9-base/root: 18.6GB ext4 / ------ debian9-base/swap: 3.72GB swap area - Up to date as of 2017-09-27 - sources.list includes: Sections: main contrib non-free Additional repository: backports - Apt-cacher configured as per Last School site (Proxy credentials will need to be entered in /etc/apt/apt.conf.d/02proxy by user) - SSH access installed and enabled - Gnome and Firefox configured to auto-detect proxy settings - Extra software installed: vlc gimp emacs fonts-indic tcpdump iperf exfat-utils wireshark - One network interface as bridged adapter, cable connected.
Added a second ethernet adapter in settings, connected to "Bridged adapter", re-initialized its MAC address
Increased the allocated CPUs to 2
The host computer has two network interfaces, one connected to a network uplink and another connected to a couple of wifi routers. Each VirtualBox virtual interface is bridged to a different physical adapter. Network configuration is now as follows (interface name seen in guest OS - Adapter name in VirtualBox settings - Adapter "Attached to" setting in VirtualBox settings - Physical interface bridged to):
enp0s3 - Adapter 1 - Bridged adapter- physical interface connected to uplink
enp0s8 - Adapter 2 - Bridged adapter - physical interface connected to wifi routers
Booted the VM, logged in to the GUI, connected using DHCP with network manager
In terminal:
rm /etc/apt/apt.conf.d/02proxy apt-get update apt-get upgrade
Rebooted the virtual machine
Set strong passwords for ls and root users
Installed my ssh public key in root's .ssh/authorized_keys file.
Installation of relevant services:
Shorewall (based on LASTSCHL-207):
apt-get install shorewall apt-get install ipset mv /etc/shorewall{,-orig} mkdir /etc/shorewall
Configuration:
root@debian9-base:/etc/shorewall# for i in `ls`; do echo "========= $i ========="; cat $i | grep -v "^#" | grep -v "^$"; echo "========= $i ========="; echo ""; done ========= hosts ========= ========= hosts ========= ========= interfaces ========= net enp0s3 detect tcpflags,dhcp,nosmurfs,routefilter,logmartians wifi enp0s8 detect tcpflags,nosmurfs,routefilter,logmartians ========= interfaces ========= ========= masq ========= enp0s3 192.168.9.0/24 ========= masq ========= ========= policy ========= $FW net REJECT INFO(uid) $FW wifi ACCEPT INFO(uid) wifi all REJECT net all DROP INFO all all REJECT info ========= policy ========= ========= routestopped ========= ========= routestopped ========= ========= rules ========= Invalid(DROP) net all ACCEPT:INFO(uid) net $FW tcp 22 ACCEPT:INFO(uid) net $FW udp 123 ACCEPT:INFO(uid) net $FW icmp ACCEPT:INFO(uid) $FW net tcp 465,587,995,993 ACCEPT:INFO(uid) $FW net udp 53,123 ACCEPT:INFO(uid) $FW net icmp ACCEPT:INFO(uid) $FW net tcp - - - - root ACCEPT:INFO(uid) $FW net udp - - - - root ACCEPT:INFO(uid) $FW net icmp - - - - root ACCEPT:INFO(uid) $FW net tcp - - - - _apt ACCEPT:INFO(uid) $FW net udp - - - - _apt ACCEPT:INFO(uid) $FW net icmp - - - - _apt ========= rules ========= ========= shorewall.conf ========= .... STARTUP_ENABLED=Yes .... IP_FORWARDING=On .... ========= shorewall.conf ========= ========= zones ========= fw firewall net ipv4 wifi ipv4 ========= zones =========
In /etc/default/shorewall, set
startup=1
root@debian9-base:~# cat /etc/rsyslog.d/40-shorewall.conf :msg, contains, "Shorewall:" /var/log/shorewall & stop root@debian9-base:~# cat /etc/logrotate.d/shorewall /var/log/shorewall-init.log { weekly rotate 108 compress nomissingok create 0640 root adm } /var/log/shorewall { rotate 731 daily nomissingok notifempty delaycompress compress dateext postrotate reload rsyslog >/dev/null 2>&1 || true endscript } root@debian9-base:~# cat /etc/logrotate.d/rsyslog /var/log/syslog /var/log/auth.log { rotate 731 daily dateext nomissingok notifempty delaycompress compress postrotate invoke-rc.d rsyslog rotate > /dev/null endscript } /var/log/mail.info /var/log/mail.warn /var/log/mail.err /var/log/mail.log /var/log/daemon.log /var/log/kern.log /var/log/user.log /var/log/lpr.log /var/log/cron.log /var/log/debug /var/log/messages { rotate 4 weekly missingok notifempty compress delaycompress sharedscripts postrotate invoke-rc.d rsyslog rotate > /dev/null endscript } root@debian9-base:~# cat /etc/logrotate.conf # see "man logrotate" for details # rotate log files weekly weekly # keep 4 weeks worth of backlogs rotate 4 # create new (empty) log files after rotating old ones create # uncomment this if you want your log files compressed #compress # packages drop log rotation information into this directory include /etc/logrotate.d # no packages own wtmp, or btmp -- we'll rotate them here /var/log/wtmp { nomissingok monthly create 0664 root utmp rotate 24 } /var/log/btmp { nomissingok monthly create 0660 root utmp rotate 24 } # system-specific logs may be configured here
systemctl enable shorewall.service
Configure network and DHCP (based on LASTSCHL-212):
systemctl disable network-manager.service systemctl disable NetworkManager.service unlink /etc/resolv.conf echo nameserver 192.168.10.1 > /etc/resolv.conf mkdir /etc/ltsp
root@debian9-base:~# cat /etc/network/interfaces # This file describes the network interfaces available on your system # and how to activate them. For more information, see interfaces(5). # The loopback network interface auto lo iface lo inet loopback # The external interface auto enp0s3 iface enp0s3 inet static address 192.168.10.52 network 192.168.10.0 netmask 255.255.255.0 broadcast 192.168.10.255 gateway 192.168.10.1 # The wifi interface auto enp0s8 iface enp0s8 inet static address 192.168.9.1 netmask 255.255.255.0 broadcast 192.168.9.255 root@debian9-base:~# cat /etc/dhcp/dhcpd.conf | grep -v "^#" | grep -v "^$" # Some of the following lines are there by default and are probably not required ddns-update-style none; option domain-name "example.org"; option domain-name-servers ns1.example.org, ns2.example.org; default-lease-time 600; max-lease-time 7200; log-facility local7; include "/etc/ltsp/dhcpd.conf"; root@debian9-base:~# cat /etc/ltsp/dhcpd.conf # # Default LTSP dhcpd.conf config file. # authoritative; subnet 192.168.9.0 netmask 255.255.255.0 { range 192.168.9.40 192.168.9.250; option domain-name "test.av"; option domain-name-servers 192.168.9.1; option broadcast-address 192.168.9.255; option routers 192.168.9.1; option subnet-mask 255.255.255.0; option root-path "/opt/ltsp/amd64"; if substring( option vendor-class-identifier, 0, 9 ) = "PXEClient" { filename "/ltsp/amd64/pxelinux.0"; } else { filename "/ltsp/amd64/nbi.img"; } }
apt-get install isc-dhcp-server
In /etc/default/isc-dhcp-server, set:
INTERFACESv4="enp0s8"
Configure DNS (based on LASTSCHL-211):
apt-get install dnsmasq touch /var/log/dnsmasq chmod 640 /var/log/dnsmasq
root@debian9-base:~# cat /etc/dnsmasq.conf | grep -v "^#" | grep -v "^$" strict-order interface=enp0s8 expand-hosts domain=test.av log-queries log-facility=/var/log/dnsmasq root@debian9-base:~# cat /etc/logrotate.d/dnsmasq /var/log/dnsmasq { rotate 731 daily nomissingok notifempty delaycompress compress dateext postrotate reload rsyslog >/dev/null 2>&1 || true endscript } root@debian9-base:~# cat /etc/hostname server.test.av root@debian9-base:~# cat /etc/hosts 127.0.0.1 localhost 192.168.9.1 test.av 192.168.9.1 server.test.av server # The following lines are desirable for IPv6 capable hosts ::1 localhost ip6-localhost ip6-loopback ff02::1 ip6-allnodes ff02::2 ip6-allrouters
New stuff
Now that we have a working setup similar to the production one, we will modify it to implement the new solution.
Download the latest version of the attached shwl_add_shwl_del_sl_pmu archive and extract it somewhere convenient.
Shorewall
Add to /etc/shorewall/hosts:
wifi1 enp0s8:dynamic
Modify /etc/shorewall/policy:
# Just after: wifi all REJECT # Added: wifi1 net ACCEPT INFO wifi1 $FW ACCEPT INFO(uid) $FW wifi1 ACCEPT INFO(uid) # Before: net all DROP INFO
Add to /etc/shorewall/zones:
.... wifi1:wifi ipv4 dynamic_shared
In /etc/shorewall/shorewall.conf set:
SAVE_IPSETS=Yes
Add to /etc/shorewall/rules (replace IP addresses with actual IP address of wifi routers):
ACCEPT:INFO(uid) wifi:192.168.9.2,192.168.9.3,192.168.9.4 $FW udp 1812
FreeRADIUS
apt-get install freeradius systemctl enable freeradius.service
Modify /etc/freeradius/3.0/mods-available/eap:
comment the following:
.... # md5 { # } .... # leap { # } .... # gtc { # # The default challenge, which many clients # # ignore.. # #challenge = "Password: " # # # The plain-text response which comes back # # is put into a User-Password attribute, # # and passed to another module for # # authentication. This allows the EAP-GTC # # response to be checked against plain-text, # # or crypt'd passwords. # # # # If you say "Local" instead of "PAP", then # # the module will look for a User-Password # # configured for the request, and do the # # authentication itself. # # # auth_type = PAP # } .... # tls { # # Point to the common TLS configuration # tls = tls-common # # # # # As part of checking a client certificate, the EAP-TLS # # sets some attributes such as TLS-Client-Cert-CN. This # # virtual server has access to these attributes, and can # # be used to accept or reject the request. # # # # virtual_server = check-eap-tls # } ....
modify the 'default_eap_type' directive under section 'eap' to be:
default_eap_type = peap
and the 'default_eap_type' directive under section 'ttls' to be:
default_eap_type = mschapv2
Modify /etc/freeradius/3.0/sites-available/default, comment the following lines (see comments included in the code block):
# All the listen sections except the IPv4 version with "type = auth" listen { ipaddr = * port = 0 type = acct limit { } } listen { type = auth ipv6addr = :: # any. ::1 == localhost port = 0 limit { max_connections = 16 lifetime = 0 idle_timeout = 30 } } listen { ipv6addr = :: port = 0 type = acct limit { } } # In the authorize section: chap mschap digest files -ldap pap # In the authenticate section: Auth-Type PAP { pap } Auth-Type CHAP { chap } Auth-Type MS-CHAP { mschap } mschap digest
Uncomment the following line in the 'authorize' section:
auth_log
Add the following line at the end of the 'post-auth' section and at the beginning of the Post-Auth-Type REJECT section:
reply_log
Add the following in the post-auth section, just before the Post-Auth-Type REJECT section:
update reply { Session-Timeout := 3600 Termination-Action := 1 }
Modify /etc/freeradius/3.0/sites-available/inner-tunnel, comment the following lines:
# The whole listen section listen { ipaddr = 127.0.0.1 port = 18120 type = auth } # In the authorize section: chap mschap files -ldap # In the authenticate section: Auth-Type PAP { pap } Auth-Type CHAP { chap } Auth-Type MS-CHAP { mschap }
Add the following line after 'filter_username' and before 'suffix' in the 'authorize' section:
auth_log
Add the following line at the end of the 'post-auth' section and at the beginning of the Post-Auth-Type REJECT section:
reply_log
Modify /etc/freeradius/3.0/radiusd.conf, set (in the 'log' section):
auth = yes
Modify /etc/freeradius/3.0/clients.conf, comment the 'client localhost' and 'client localhost_ipv6' section and add (replace with actual IP addresses of wifi routers):
client wifi-ap1 { ipaddr = 192.168.9.2 secret = password # Replace with an actual password } client wifi-ap2 { ipaddr = 192.168.9.3 secret = password # Replace with an actual password } client wifi-ap3 { ipaddr = 192.168.9.4 secret = password # Replace with an actual password }
Modify /etc/logrotate.d/freeradius, modify the following options as follows ('dateext' option needs to be added):
rotate 732 nomissingok dateext
rm /var/log/freeradius/radius.log rm /var/log/freeradius/radwtmp chmod o-rwx /var/log/freeradius chown freerad:freerad /var/log/freeradius chmod o-rwx /etc/freeradius
It has been observed that radius.log comes with world-readable permissions upon installation of the package, deleting it causes FreeRADIUS to re-create it, and it gets re-created with more secure permissions. /etc/freeradius also comes with the executable bit set for all users, which makes it easier for sensitive information contained within to be world-readable in case the permissions of an individual file are not set restrictive enough (as was, by default, the case with the file containing the encryption passwords for the SSL certificates). Could not find any information on the net on whether there is a good reason for the executable bit being set, so, decided it is safer to remove it.
Certificates
Modify /etc/freeradius/3.0/certs/server.cnf, set the following settings:
... [ req ] ... input_password = password # Replace with an actual password output_password = password # Replace with an actual password, should be same as input_password ... [certificate_authority] countryName = IN stateOrProvinceName = Tamil Nadu localityName = Auroville organizationName = Test emailAddress = admin@test.av commonName = "Test Certificate Authority" ...
Modify /etc/freeradius/3.0/certs/ca.cnf, set the following settings:
... [ CA_default ] ... crlDistributionPoints = URI:http://server.test.av/test_ca.crl [ req ] ... input_password = password # Replace with an actual password output_password = password # Replace with an actual password, should be same as input_password [server] countryName = IN stateOrProvinceName = Tamil Nadu localityName = Auroville organizationName = Test emailAddress = admin@test.av commonName = "Test Server Certificate" [v3_ca] ... crlDistributionPoints = URI:http://server.test.av/test_ca.crl ...
cd /etc/freeradius/3.0/certs rm -f *.pem *.der *.csr *.crt *.key *.p12 serial* index.txt* # This step is probably not needed '@@@' make ca.pem make ca.der make server.pem make server.csr chown freerad:freerad * chmod o-rwx * rm bootstrap rm passwords.mk # Delete all other files in the folder except: server.cnf, ca.cnf, xpextensions, Makefile, README, dh, ca.pem, server.pem, server.key
Modify /etc/freeradius/3.0/mods-available/eap, modify the following directives under section 'tls-config tls-common' to be:
private_key_password = password # Replace password with the password chosen previously '@@@' same or different? private_key_file = /etc/freeradius/3.0/certs/server.pem .... certificate_file = /etc/freeradius/3.0/certs/server.pem .... ca_file = /etc/freeradius/3.0/certs/ca.pem
MySQL
apt-get install mysql-server freeradius-mysql mysql -uroot CREATE DATABASE radius; exit mysql -uroot radius < /etc/freeradius/3.0/mods-config/sql/main/mysql/schema.sql
Edit /etc/freeradius/3.0/mods-config/sql/main/mysql/setup.sql. Modify the following lines:
CREATE USER 'radius'@'localhost'; SET PASSWORD FOR 'radius'@'localhost' = PASSWORD('radpass');
to
CREATE USER 'freerad'@'localhost' IDENTIFIED VIA unix_socket;
and update the username 'radius' to be 'freerad' wherever else it is mentioned in the file.
mysql -uroot radius < /etc/freeradius/3.0/mods-config/sql/main/mysql/setup.sql
cd /etc/freeradius/3.0/mods-enabled ln -s ../mods-available/sql sql
In /etc/freeradius/3.0/mods-enabled/sql, set the following options:
driver = "rlm_sql_mysql" dialect = "mysql" server = "localhost" port = 3306 login = "freerad" password = "" radius_db = "radius" logfile = ${logdir}/sqllog.sql
Modify /etc/freeradius/3.0/sites-enabled/inner-tunnel, find the following line under authorize, post-auth and Post-Auth-Type REJECT sections
-sql
modify it to
sql
Modify /etc/freeradius/3.0/sites-enabled/default, find the following line under authorize, post-auth and Post-Auth-Type REJECT sections
-sql
In the post-auth and Post-Auth-Type REJECT sections, modify it to
sql
In the authorize section, comment it out.
Python module / script_launcher.py script
apt-get install libpython2.7-dev # It is not fully sure whether this package is needed cd /etc/freeradius/3.0/mods-enabled ln -s ../mods-available/python python
Put the following in it:
# # Make sure the PYTHONPATH environmental variable contains the # directory(s) for the modules listed below. # # Uncomment any func_* which are included in your module. If # rlm_python is called for a section which does not have # a function defined, it will return NOOP. # python { module = script_launcher python_path = ${modconfdir}/${.:name}:/usr/lib/python2.7 mod_post_auth = ${.module} func_post_auth = post_auth }
Modify /etc/freeradius/3.0/sites-enabled/inner-tunnel:
... # Add this line just after 'sql' in the 'post-auth' section python ...
Modify /etc/freeradius/3.0/mods-available/eap, modify the 'copy_request_to_tunnel' directive under both sections 'peap' and 'ttls' to be:
copy_request_to_tunnel = yes
Place the script_launcher.py script from the shwl_add_shwl_del_sl_pmu archive at /etc/freeradius/3.0/mods-config/python/script_launcher.py
chown freerad:freerad /etc/freeradius/3.0/mods-config/python/script_launcher.py chmod 640 /etc/freeradius/3.0/mods-config/python/script_launcher.py
sudo
apt-get install sudo
Create /etc/sudoers.d/shwl_add_shwl_del_pmu, permissions 640 root:root, with:
freerad ALL=(root:root) NOPASSWD:/sbin/shorewall,/usr/bin/arp-scan
shwl_add / shwl_del scripts
Prerequisites from above steps: sudo, FreeRADIUS python module / script_launcher.py script, shorewall, FreeRADIUS MySQL
apt-get install arp-scan # Install the shwl_*.sh scripts from the shwl_add_shwl_del_sl_pmu archive in /usr/local/sbin/ chown root:freerad /usr/local/sbin/shwl_* chmod 750 /usr/local/sbin/shwl_* mkdir /var/local/shwl_add chown freerad:freerad /var/local/shwl_add chmod 700 /var/local/shwl_add chmod a-s /var/local/shwl_add
Add the following line to freerad's crontab
*/1 * * * * /usr/local/sbin/shwl_del.sh # '@@@' figure out optimal interval
Settings in /usr/local/sbin/shwl_add.sh (at top of file):
.... # Settings cfg_shwl_zone="wifi1" # Shorewall dynamic zone to which client devices' IP addresses need to be added # '@@@' figure out a few optimal intervals cfg_shwl_retry_delay=2 # Number of seconds to wait, in case of failure in adding IP to shorewall dynamic zone, before attempting second time cfg_file_location="/var/local/shwl_add" # Folder where runtime information will be stored cfg_file_location_owner_user="freerad" # User by which above folder should be owned cfg_file_location_owner_group="freerad" # Group by which above folder should be owned cfg_ip_srch_iface="enp0s8" # Network interface on which to scan for devices cfg_ip_srch_initial_delay=0.75 # How many seconds to wait before first attempt at scanning cfg_ip_srch_retry_delay=4 # How many seconds to wait in between further attempts at scanning cfg_ip_srch_max_attempts=50 # Maximum number of attempts at scanning before giving up cfg_mysql_user="freerad" # MySQL username cfg_mysql_db="shwl_add_shwl_del_pmu" # MySQL database name where to log events cfg_mysql_log_table="event_log" # Table in MySQL database where to log events ....
Settings in /usr/local/sbin/shwl_del.sh (at top of file):
.... # Settings cfg_ip_match_pattern="192.168." # Pattern to match all IP addresses that might be in the shorewall dynamic zone # '@@@' figure out a few optimal intervals cfg_session_expiry_timeout=3660 # Session duration (should be slightly longer than Session-Timeout attribute specified in FreeRADIUS) cfg_shwl_zone="wifi1" # Shorewall dynamic zone containing clients' IP addresses cfg_file_location="/var/local/shwl_add" # Folder where runtime information is stored cfg_file_location_owner_user="freerad" # User by which above folder should be owned cfg_file_location_owner_group="freerad" # Group by which above folder should be owned cfg_mysql_user="freerad" # MySQL username cfg_mysql_db="shwl_add_shwl_del_pmu" # MySQL database name where to log events cfg_mysql_log_table="event_log" # Table in MySQL database where to log events ....
MySQL
mysql -uroot CREATE DATABASE shwl_add_shwl_del_pmu; GRANT ALL on shwl_add_shwl_del_pmu.event_log TO 'freerad'@'localhost'; exit mysql -uroot shwl_add_shwl_del_pmu < shwl_add_shwl_del_pmu.sql # Updating shwl_add_shwl_del_pmu.sql to the full path of the shwl_add_shwl_del_pmu.sql file extracted from the shwl_add_shwl_del_sl_pmu archive
pam_to_mysql_update.sh script
Prerequisities from above: sudo, FreeRADIUS MySQL, shwl_add / shwl_del scripts MySQL
apt-get install libpam-script sshpass mkdir /usr/share/libpam-script/pam-script.d/pam_to_mysql_update cd /usr/share/libpam-script/pam-script.d/pam_to_mysql_update # Install the pam_to_mysql_update.sh script from the shwl_add_shwl_del_sl_pmu archive in here ln -s pam_to_mysql_update.sh pam_script_auth ln -s pam_to_mysql_update.sh pam_script_passwd mysql -uroot GRANT ALL on radius.radcheck TO 'freerad'@'localhost'; exit pam-auth-update # And, uncheck the box for "Support for authentication by external scripts"
Add the following line at the end of /etc/pam.d/common-auth:
.... auth required pam_script.so onerr=fail dir=/usr/share/libpam-script/pam-script.d/pam_to_mysql_update/
Add the following line at the end of /etc/pam.d/common-password:
.... password required pam_script.so onerr=fail dir=/usr/share/libpam-script/pam-script.d/pam_to_mysql_update/
Settings in /usr/share/libpam-script/pam-script.d/pam_to_mysql_update/pam_to_mysql_update.sh (at top of file):
.... # Settings cfg_mysql_user="freerad" # MySQL username cfg_mysql_user_db="radius" # MySQL database name where to update passwords cfg_mysql_log_db="shwl_add_shwl_del_pmu" # MySQL database name where to log events cfg_mysql_user_table="radcheck" # Table in MySQL database where to update passwords cfg_mysql_log_table="event_log" # Table in MySQL database where to log events cfg_verbose=0 # Print verbose messages on stdout ....
Managing users
The below procedures also create/change password for/delete system users as well as users for FreeRADIUS.
Adding users
Replace 'user' with the desired username.
mysql -uroot use radius; INSERT INTO radcheck VALUES ('','user','NT-Password',':=',''); exit adduser user # When prompted for "Current password:", ignore and press enter
Changing password
It is sufficient to use standard utilities such as 'passwd', the password will be updated in the MySQL database as well. Tested with 'passwd' and User Accounts applet in GNOME. In case prompted with "Current password:" (exactly as written here) it is sufficient to ignore and press enter. Commands that expire or disable a user's system user account (or password) without deleting it (such as passwd -l) will not cause the credentials in the MySQL database to be disabled, thus it is necessary to take care (perhaps with a site specific lock user script) to also invalidate the same.
Deleting users
Replace 'user' with the username to be deleted.
mysql -uroot use radius; DELETE FROM radcheck WHERE username='user'; exit deluser user
WiFi router (NAS) configuration
Settings to be configured
These are the settings that usually need to be configured, on dual-band routers it might be necessary to configure some of the settings twice, once under the settings for the 2.4GHz SSID and once for the 5GHz SSID:
- SSID - SSID of choice
- Channels - '@@@'
- Network security type: WPA2 Enterprise
- WPA type: Set to either Auto or WPA2
- WPA encryption: Set to either Auto or AES
- RADIUS server IP - 192.168.9.1
- RADIUS server port - 1812
- RADIUS server secret/password - Password chosen in clients.conf for this particular NAS
- IP address - IP address needs to match IP mentioned in clients.conf
- Disable DHCP
- Some models: Reauthentication period - Specify to something equal to or greater than the Session-Timeout specified in /etc/freeradius/3.0/sites-available/default. Some NASes interpret 0 as disabling re-authentication, and might then also ignore any value mentioned by the FreeRADIUS Session-Timeout / Termination-Action attributes.
- Secure password - Choose a secure password for accessing the NAS web (or other) interface. It is important as it controls access to the wireless security settings, and the web (or other) interface is reachable by supplicants connected to the network.
- Some models: Operation mode - Some NASes have an Operation mode setting, which sets/locks some settings to defaults that are appropriate for different kinds of uses, e.g. "DSL Router", "Wireless Router", "Wireless Access Point". This varies by model, but usually something like "Wireless Access Point" is a good first choice, if available, alternatively "Wireless Router"
TP-Link Archer C20 v4 00000004
In this model, the "Reauthentication period" setting is not available, but the router does honor the timeout specified by the RADIUS server. Operation mode can be set to "Access Point". All other settings should be set as mentioned above. This is a dual band router and some settings need to be set in two places, once for each SSID.
TP-Link TD-W8968 V4 0x00000001
In this model, the "Reauthentication period" setting is available as "Network Re-auth Interval", and the router does honor the timeout specified by the RADIUS server overriding the setting specified here if it is lower '@@@'. Operation mode can be set to "Wireless Router Mode". All other settings should be set as mentioned above.
TP-Link TL-WR740N v4 00000000
In this model, the "Reauthentication period" setting is not available, and the router does not honor the timeout specified by the RADIUS server. Judging by the source code of the very old version of hostapd running on this router, it is believed (but not tested) that, once authenticated, the router might allow the supplicant to continue being part of the network for up to twelve hours without querying the RADIUS server again. No operation mode setting is available '@@@'. All other settings should be set as mentioned above.
Supplicant configuration
Linux
- Copy the .ca file generated during certificate generation onto the computer.
- Select the network's SSID from the list in Network Manager.
- When asked, enter the following information, then press connect:
CA certificate: Browse and select the .ca file
Identity: the username
Password: the password
Leave all other fields as they are
Android
- Copy the .ca file generated during certificate generation onto the phone.
- Open the “Settings” app, go to “Wi-Fi” → “Advanced settings” → “Install certificates”.
- Select the .ca file.
- Assign it a name of choice
- Under “Certificate use” select “WiFi”
- Once again, open the “Settings” app, go to “Wi-Fi”, and select the network's SSID from the list.
- When asked, enter the following information, then press connect:
CA certificate: Select the earlier chosen name when installing the .ca file
Identity: the username
Password: the password
Leave all other fields as they are
Windows 10
- Select the network's SSID from the list of wireless networks
- Enter username and password
- When prompted whether to trust the server, confirm
Mac OS
- Select the network's SSID from the list of wireless networks
- Enter username and password
- When prompted whether to trust the server, confirm
iPhone
- Select the network's SSID from the list of wireless networks
- Enter username and password
- When prompted whether to trust the server, confirm
Security observations
On Linux and Android supplicants it is required to install the .ca file generated during certificate generation in order to verify the RADIUS server's identity. In case the identity presented by the RADIUS server changes at any point, the supplicant fails to connect, and re-presents the user with the prompt for network credentials. It is possible to connect without installing the .ca file, but one needs to specify "No CA certificate required" or "Do not validate". In this case the supplicant will send credentials to any RADIUS server for that SSID without verifying its identity. It is possible to avoid sending the real user name in the unencrypted outer tunnel, by specifying a different value (normally 'anonymous') in the "Anonymous identity" field.
On Mac OS and iPhone supplicants, when connecting to the SSID for the first time, the server certificate's details are presented to the user and the user is asked if they want to trust the server. In case the identity presented by the RADIUS server changes at any point, the user will be prompted with a message, not containing any warning, sadly, that looks identical to the one displayed when connecting for the first time, where a user is extremely likely to press Trust once again. On Mac OS, it is also possible to copy the .ca file and install it, avoiding the prompt on first connect, on iPhone, on the iPhone this was tested on, this did not have any effect. It seems to be possible, but greatly complicated (involving installing a software from the App Store, and using it to create a configuration profile which then needs to be saved to a file, copied and imported onto the supplicant device) to configure the supplicant to not send the real user name in the unencrypted outer tunnel.
Windows 10 '@@@'
Sources
https://wiki.freeradius.org/guide/Basic-configuration-HOWTO
https://wiki.freeradius.org/guide/SQL-HOWTO-for-freeradius-3.x-on-Debian-Ubuntu
https://wiki.freeradius.org/modules/Rlm_python
https://wiki.freeradius.org/config/Certificates
http://deployingradius.com/documents/configuration/certificates.html
http://deployingradius.com/documents/protocols/compatibility.html