Freeradius with MIT kerberos Authentication
===========================================
I have successfully installed and configured MIT kerberos and Freeradius Authentication. This might be helpful for some people who are interested in doing this. Perhaps FR guys will add this into their wiki.
Why I am doing this ?
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I have been running Eduroam service on freeradius and Active Directory for user authentication. In order to use Active Directory, I had to configure samba and winbind. Lately, I had too many problems
with winbind and samba which require frequent restart the daemon both smb and winbind. I ended up writing some cron to do this for me. I feel this is not reliable and looked for alternative solution. I came up
with four different solution.
1. Continue using Freeradius with Active directory for user authentication and maintain ill winbind plus samba
2. Customize the LDAP (openLdap) so that password can be stored in NT-HASH or LMHASH or whatever is compatible, so you do not have to worry about SMB, Winbind
3. Forget about FreeRadius and choose Microsoft IAS or their $ application so that you do not have to worry samba,winbind freeradius :)
4. Deploy kerberos, integrate with OpenLDAP, configure FreeRadius to use Kerberos for user authentication.
I preferred point number 4. and implemented, Now since it is working fine I am thinking of going in production. Here is what I did:
I assume you have already working Kerberos server if not here are the instruction how to install MIT kerberos in LINUX
1. Add the hostprincipal and service principal for your Freeradius server
2. Add user principal for testing:
kadmin$ add_principal krbtesting # this will prompt you a password - just type whatever you want, in my case I typed krbtesting as my password
3. you need to dump the keytab file,
4. so you have the keytab file, if you like test it. This can be done as this :
5. Copy krb5.keytab file to your freeradius server
You are done with Kerberos. let install the freeradius
On Centos you can do :
=================
test15# yum install freeradius freeradius-krb5 freeradius-utils -y
For basic kerberos authentication test you just need to configure few files under /etc/raddb
1. Edit /etc/raddb/modules/krb5.conf and add the following
krb5 {
keytab = /etc/krb5.keytab # make sure this keytab file is readble by radius daemon change the path where your keytab file is
}
2. Add Auth-Type kerberos in /etc/raddb/sites-enabled/default right after the PAP like this:
Auth-Type Kerberos {
krb5
}
PS: Kerberos only works with PAP
3. Add DEFAULT AUTH-Type = kerberos (without quote "") on top of your /etc/raddb/users file
4. Now, start your freeradius in debug mode, radiusd -X
Lets test the authentication, open another terminal and issue the following command:
test15$ radtest krbtesting krbtesting localhost 0 testing123
Where, username is krbtesting and password is krbtesting, radiusserver is localhost and seceret is testing123. The aim here is to get Accept-Accept, here is what I get:
Fri Dec 28 10:50:57 2012 : Info: ++[expiration] returns noop
Fri Dec 28 10:50:57 2012 : Info: ++[logintime] returns noop
Fri Dec 28 10:50:57 2012 : Info: [pap] WARNING! No "known good" password found for the user. Authentication may fail because of this.
Fri Dec 28 10:50:57 2012 : Info: ++[pap] returns noop
Fri Dec 28 10:50:57 2012 : Info: Found Auth-Type = Kerberos
Fri Dec 28 10:50:57 2012 : Info: # Executing group from file /etc/raddb/sites-enabled/default
Fri Dec 28 10:50:57 2012 : Info: +- entering group kerberos {...}
Fri Dec 28 10:50:57 2012 : Debug: rlm_krb5: verify_krb_v5_tgt: host key not found : Permission denied
Fri Dec 28 10:50:57 2012 : Info: ++[krb5] returns ok
Fri Dec 28 10:50:57 2012 : Auth: Login OK: [krbtesting] (from client localhost port 0)
Fri Dec 28 10:50:57 2012 : Info: # Executing section post-auth from file /etc/raddb/sites-enabled/default
Fri Dec 28 10:50:57 2012 : Info: +- entering group post-auth {...}
Fri Dec 28 10:50:57 2012 : Info: [reply_log]
expand: /var/log/radius/radacct/%{Client-IP-Address}/reply-detail-%Y%m%d -> /var/log/radius/radacct/
127.0.0.1/reply-detail-20121228Fri Dec 28 10:50:57 2012 : Info: [reply_log] /var/log/radius/radacct/%{Client-IP-Address}/reply-detail-%Y%m%d expands to /var/log/radius/radacct/
127.0.0.1/reply-detail-20121228Fri Dec 28 10:50:57 2012 : Info: [reply_log] expand: %t -> Fri Dec 28 10:50:57 2012
Fri Dec 28 10:50:57 2012 : Info: ++[reply_log] returns ok
Fri Dec 28 10:50:57 2012 : Info: ++[exec] returns noop
Sending Access-Accept of id 248 to 127.0.0.1 port 34456
The key thing here is to get Login OK and krb5 returns ok, if you see those you have successfully authenticated against your freeradius with kerberos server. There is warning and permission denied messages,
see earlier post and Alan's reply.
on your terminal you will see output as this :
[test@test15]# radtest krbtesting krbtesting localhost 0 testing123
Sending Access-Request of id 248 to 127.0.0.1 port 1812
User-Name = "krbtesting"
User-Password = "krbtesting"
NAS-IP-Address = 192.168.1.25
NAS-Port = 0
Message-Authenticator = 0x00000000000000000000000000000000
rad_recv: Access-Accept packet from host 127.0.0.1 port 1812, id=248, length=20
I have tested EAP-TTLS - PAP with wpa_supplicant and it works well too. Also I tested following devices that allows EAP-TTLS and PAP:
Sonny Ericksson mobile
samsung galaxy s II
samsung galaxy note
windows 8 (thank you Dr. Bill you enabled other selection apart from PEAP)
Fedora 17
windows 7 requries securew2 to make it work (it works though)
Hope this helps.