Well, thanks to an inordinate amount of help,
I've got my RADIUS server up and running exactly how I want it to.
As part of my business process, I've got a
detailed doc on how the server is/was
constructed. I'd like to contribute that to the
wiki, but I don't see that I can create an account.
Also, since it drives me nuts when I'm searching
on line for a fix, and an email thread ends JUST
before I have the data that I need, or a piece is
missing, here's that documentation as well
Rick Steeves 091201
[email protected]
Setup and configuration instructions, on CentOS 5.x
Goals:
o Authentication telnet sessions for Cisco
switches against AD for a specific security group (Infrastructure)
o Authentication for VPN users using MSCHAP
on a sonicwall firewall using a Windows VPN
client with L2TP against AD for a specific security group (VPN_Users)
Install
The linux site for the rpm download of freeradius2 is:
http://people.redhat.com/jdennis/freeradius-rhel-centos
Create /etc/yum.repos.d/freeradius2.repo:
[freeradius2]
name=Freeradius2
baseurl=http://people.redhat.com/jdennis/freeradius-rhel-centos
enabled=1
gpgenabled=0
Install freeradius2:
yum install freeradius2 freeradius2-utils freeradius2-ldap
Enable FreeRadius to start on boot:
chkconfig radiusd on
To start the freeRadius service
service radiusd start
To run the service in debug mode (which you
should be doing until everything works):
service radiusd stop
radiusd X
Configuration
http://deployingradius.com/documents/configuration/active_directory.html
Note that the configuring of SAMBA, kerberos, and
adding to the domain should already be done as
part of the default Linux install, see
h:\is\operating system\Linux\Guide_linux.doc
Verify that a user in the domain can be authenticated:
wbinfo -a user%password
Try the same login with the ntlm_auth program,
which is what FreeRADIUS will be using:
ntlm_auth --request-nt-key --domain=MYDOMAIN
--username=user --password=password
./raddb/radiusd.conf (see Appendix C)
Update max_requests to # users * 256
Add to the end of the auth listen {..}
clients = disambiguate
Add to the end of the acct listen {..}
clients = disambiguate
Add to the end of the modules{..} section:
exec ntlm_auth {
wait = yes
program = "/usr/bin/ntlm_auth ntlm_auth
--request-nt-key --domain=example.com
-username=%{mschap:User-Name} --password=%{User-Password}"
}
In log {..}
auth = yes
huntgroups
huntgroups let you restrict which clients are
associated with which user. You will need to add
each IP of each device that will be using the
RADIUS server, and associate it with the correct
huntgroup. This will let the ./users file
associate the user with the appropriate device:
/etc/radbb/huntgroups:
Cisco_Huntgroup NAS-IP-Address == 10.100.0.1
Cisco_Huntgroup NAS-IP-Address == 10.100.0.2
Cisco_Huntgroup NAS-IP-Address == 10.100.0.3
VPN_Huntgroup NAS-IP-Address == 10.4.1.2
./raddb/modules/ldap (See appendix D)
If this file is missing, you need to install the RPM for freeradius2-ldap.
This section is one of the biggest pains to
configure, as all of your LDAP strings need to be
100% correct, andt hey will be very specific to
the environment. Of course, update server,
identify, password, basedn for your own environment.
You will need a user account in AD to permit the
bind to LDAP. In this example, that account is in:
CN=_useraccount,OU=Service Accounts,OU=Special
User Accounts,OU=Enterprise,DC=example,DC=com
In this example, the Security groups are located in (or below):
OU=Enterprise,DC=example,DC=com
ldap {
server = "example.com"
identity = "CN=_useraccount,OU=Service
Accounts,OU=Special User Accounts,OU=Enterprise,DC=example,DC=com"
password = secretpassword
basedn = "OU=Enterprise,DC=example,DC=com"
filter =
(&(sAMAccountname=%{Stripped-User-Name:-%{User-Name}})(objectClass=person))
groupmembership_attribute = "memberOf"
ldap_connections_number = 5
timeout = 4
timelimit = 3
net_timeout = 1
tls {
start_tls = no
}
dictionary_mapping = ${confdir}/ldap.attrmap
edir_account_policy_check = no
groupname_attribute = cn
groupmembership_filter =
"(|(&(objectClass=GroupOfNames)(member=%{control:Ldap-UserDn}))(&(objectClass=GroupOfUniqueNames)(uniquemember=%{control:Ldap-UserDn})))"
}
Configuration of different virtual sites
For this you'll have 3 general sites, default
(used mostly for testing on 127.0.0.1),
server_cisco (used to AAA the Cisco users), and
server_vpn (used to AAA the VPN users).
inner-tunnel
Add:
ntlm_auth
to the end of the authenticate{..} section
default
Add:
ntlm_auth
to the end of the authenticate{..} section
server_cisco (see Appendix B)
We're going to duplicate the default config, and
modify it for that particular virtual server:
cp /etc/raddb/sites-available/default /etc/raddb/sites-available/server_cisco
Edit server_cisco and change it from server{..} to server server_cisco{..}
Since we're not using any of these methods for
the Ciscos, in authenticate{..} disable: chap,
mschap, suffix, ntdomain, unix, pap
Add to the end of the authorize{..} section:
ntlm_auth
server_vpn (see Appendix A)
cp /etc/raddb/sites-available/server_cisco
/etc/raddb/sites-available/server_vpn
Edit server_vpn and change it from server
server_cisco {..} to server server_vpn {..}
To get it to restrict who gets authorized based
on the LDAP group, add to authorize {..}:
if(Huntgroup-Name == "VPN_Huntgroup") {
if(Ldap-Group == "VPN_Users") {
ok
}
else {
reject
}
}
Link sites-enabled to sites-available:
cd /etc/raddb/sites-enabled
ln s ../sites-available/server_cisco server_cisco
ln s ../sites-available/server_vpn server_vpn
./raddb/clients.conf
This defines which individual clients connect to
which virtual server, letting you differentiate
the server config (including the secret) by client
Note: The secret needs to match the secret set on
the respective client. Change the secret to an actual secret
clients disambiguate {
client localhost {
ipaddr = 127.0.0.1
secret = testing123
require_message_authenticator = no
}
client VPN {
ipaddr = 10.4.1.2
secret = secret
virtual_server = server_vpn
}
client Cisco {
ipaddr = 10.100.0.0
netmask = 16
secret = secret
virtual_server = server_cisco
nastype = cisco
}}
./raddb/users
This file determines which AAA is done against
which device and associates the defined huntgroups with the type of AAA
#testuser Huntgroup-Name == Cisco_Huntgroup, Cleartext-Password:="testpass"
# Service-Type:=NAS-Prompt-User,cisco-avpair:="shell:priv-lvl=15"
DEFAULT Huntgroup-Name == Cisco_Huntgroup,
Auth-Type:=ntlm_auth, Ldap-Group == "Infrastructure"
Service-Type:=NAS-Prompt-User,cisco-avpair:="shell:priv-lvl=15"
DEFAULT Huntgroup-Name == VPN_Huntgroup, Ldap-Group == "VPN_Users"
Cisco config
On each switch, you have to point the
authentication, authorization, and accounting to
the RADIUS server. You'll want to have defined
login and enable passwords already in case you
screw up. you can then just bring the RADIUS
server down and it will default to the next form of authentication:
aaa authentication login default group radius line
aaa authentication enable default group radius line
aaa authorization exec default group radius none
no aaa accounting exec default start-stop group radius
no aaa accounting system default start-stop group radius
no aaa accounting network default start-stop group radius
no aaa accounting connection default start-stop group radius
no aaa accounting commands 1 default stop-only group radius
no aaa accounting commands 15 default wait-start group radius
radius host 10.10.20.24 auth-port 1812 acct-port 1813 timeout 3
radius key <mysharedsecret>
radius retransmit 2
sonicwall config
Sorry, outside the scope of this document.
Different Testing methods
From Windows:
Ntradping.exe
From Linux:
radtest testuser testpass localhost 0 testing123
ntlm_auth --request-nt-key --domain=example.com
--username=testuser --password=testpass
Troubleshooting:
If you get an error from the output of radiusd X along the lines of:
Exec-Program output: winbind client not
authorized to use winbindd_pam_auth_crap. Ensure
permissions on
/var/cache/samba/winbindd_privileged are set correctly. (0xc0000022)
hen the issue is that radiusd doesn't have access
to the winbindd_privileged folder. you can fix with:
chgrp radiusd /var/cache/samba/winbindd_privileged
chmod g+rw /var/cache/samba/winbindd_privileged
Appendix A server_vpn
server server_vpn {
authorize {
preprocess
mschap
files
ldap
if(Huntgroup-Name == "VPN_Huntgroup") {
if(Ldap-Group == "VPN_Users") {
ok
}
else {
reject
}
}
}
authenticate {
Auth-Type PAP {
pap
}
Auth-Type CHAP {
chap
}
Auth-Type MS-CHAP {
mschap
}
ntlm_auth
}
preacct {
preprocess
acct_unique
files
}
accounting {
detail
radutmp
attr_filter.accounting_response
}
session {
radutmp
}
post-auth {
exec
Post-Auth-Type REJECT {
attr_filter.access_reject
}
}
pre-proxy {
}
post-proxy {
}
}
Appendix B: server_cisco
server server_cisco {
authorize {
preprocess
mschap
files
ldap
}
authenticate {
Auth-Type PAP {
pap
}
Auth-Type CHAP {
chap
}
Auth-Type MS-CHAP {
mschap
}
ntlm_auth
}
preacct {
preprocess
acct_unique
files
}
accounting {
detail
radutmp
attr_filter.accounting_response
}
session {
radutmp
}
post-auth {
exec
Post-Auth-Type REJECT {
attr_filter.access_reject
}
}
pre-proxy {
}
post-proxy {
}
}
Appendix C radiusd.conf
prefix = /usr
exec_prefix = /usr
sysconfdir = /etc
localstatedir = /var
sbindir = /usr/sbin
logdir = ${localstatedir}/log/radius
raddbdir = ${sysconfdir}/raddb
radacctdir = ${logdir}/radacct
name = radiusd
confdir = ${raddbdir}
run_dir = ${localstatedir}/run/${name}
db_dir = ${raddbdir}
libdir = /usr/lib/freeradius
pidfile = ${run_dir}/${name}.pid
user = radiusd
group = radiusd
max_request_time = 30
cleanup_delay = 5
max_requests = 25600
listen {
type = auth
ipaddr = *
port = 0
clients = disambiguate
}
listen {
ipaddr = *
port = 0
type = acct
clients = disambiguate
}
hostname_lookups = no
allow_core_dumps = no
regular_expressions = yes
extended_expressions = yes
log {
destination = files
file = ${logdir}/radius.log
syslog_facility = daemon
stripped_names = no
auth = yes
auth_badpass = no
auth_goodpass = no
}
checkrad = ${sbindir}/checkrad
security {
max_attributes = 200
reject_delay = 1
status_server = yes
}
proxy_requests = yes
$INCLUDE proxy.conf
$INCLUDE clients.conf
thread pool {
start_servers = 5
max_servers = 32
min_spare_servers = 3
max_spare_servers = 10
max_requests_per_server = 0
}
modules {
$INCLUDE ${confdir}/modules/
exec ntlm_auth {
wait = yes
program = "/usr/bin/ntlm_auth
ntlm_auth --request-nt-key --domain=example.com
--username=%{mschap:User-Name} --password=%{User-Password}"
}
}
instantiate {
exec
expr
expiration
logintime
}
$INCLUDE policy.conf
$INCLUDE sites-enabled/
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