Cisco AAA VPN and RADIUS on Mac OS X Server 10.8 – Mountain Lion

So you’re using Mountain Lion Server for Open Directory. Good for you! But beware of your users, they have requested VPN access to the network and like any good sysadmin you think, “Jesus H Christ, here’s yet another credential combo for the user to forget, for the user to call me at 10pm Friday night asking: ummmmmm, what’s my password?” FOR WHAT?!?! Jeezus Christ why don’t they ever tell us which password they forgot? Anywho, I digressed. Well with the power of RADIUS on your trusty Mac OS X Server you can now defer the authentication of your Cisco VPN gateway to your directory system. Let’s setup RADIUS on Mac OS X Server.

Prep the directory

Either you Mac an OD Master or bind to a directory, I think this is a given but, just saying. Then, whatever directory system you’re using, you must create a group called “VPN Access” or something to that effect, and subscribe the users and/or groups you want to have access to VPN. I don’t care if this is in Active Directory or Workgroup Manager or Server.app.

Build the RADIUS service

ARD into your Mac OS X server. In Server.app navigate to your hardware and then Settings. Note which SSL certificate your server is currently using and then find that certificate in Keychain Access. Right below it will be the key, right click on the key and choose Export, the destination will be /Users/Shared/cert.p12 and the password can be blank.

Open Workgroup Manager and edit local directory, authenticate yourself so you have read/write privileges. From the view menu enable Show System Records, then click on the groups tab, sort by GID. Scroll down to the 200’s and look for records like “com.apple.ard_access” “com.apple.afp_access” find the last of these groups and note the GID. Now create a new group, the long name is blank, the short name is “com.apple.access_radius” and the GID is incremented by 1 from the last GID you noted earlier. Save changes. GID  2xx

Once created click on the members tab and then “+” symbol. A side pane will appear, in this pane you can choose any directory system the OS X box is bound to, active or open. Cool hey?  Add “VPN Access” group. Save the changes.

Open a terminal and “sudo -s” up. As the root user paste in the following:
radiusconfig -setconfig auth yes
radiusconfig -setconfig auth_badpass yes
radiusconfig -setconfig auth_goodpass no
radiusconfig -autorotatelog on -n 15


Now, run these one at a time, when prompted for password, enter the password that you set when you exported the cert from Keychain, I told you to put no password but God knows that sysadmins rarely do what they’re told. 😉

paste one at a time:
WATCH THE LINE WRAP!

openssl pkcs12 -in /Users/Shared/cert.p12 -out /etc/raddb/certs/radius.key -nodes -nocerts
openssl pkcs12 -in /Users/Shared/cert.p12 -out /etc/raddb/certs/radius.crt -nodes -nokeys
radiusconfig -installcerts /etc/raddb/certs/radius.key /etc/raddb/certs/radius.crt


Finally for the server let’s grant access to our Cisco box, IP is obviously the IP of the box, short-name is just a nickname for the system.
radiusconfig -addclient <IP> <short-name> other

You should be prompted to enter a key, please remember this key, let’s call it: theKey.

finally run radius in verbose with radiusd -X Leave the terminal open, do not close. It will help us deduce answers should problems arise. If all goes well you should get something like:

Listening on authentication *:1645
Listening on accounting *:1646
Ready to process requests.


Connect your Cisco VPN gateway

conf t
radius-server host <enter IP||FQDN> auth-port 1812 acct-port 1813
radius-server key <enter theKey>
aaa new-model
aaa authentication login vpn group radius local
aaa authorization network vpn local


You’ll need to connect this AAA stanza to your crypto map, my crypto map is called VPN. This is how I did it, note the bold similarities.

crypto map VPN client authentication list vpn
crypto map VPN isakmp authorization list vpn


This will allow AAA to check the RADIUS server, but fall back to local auth if RADIUS does not respond.

Finally we’re going to test all of this by using the test command. So get out of conf t by typing exit and try the following:

test aaa group radius <username> <password> legacy


If it returns “User was successfully authenticated.” You’re in business. Also, note the terminal where radiusd -X is running, you’ll see some interesting output.

Clean Up

wr mem on your router and exit the session. Cancel that radiusd -X process we started and set the process to run. serveradmin start radius Immediately test the connection from the outside to ensure it’s stable.

Check out my next post: Authenticate APC UPS against RADIUS on Mac OS X Server 10.8 Mountain Lion

Apple Certified Technical Coordinator (ACTC) OS X Server Essentials 10.8 Test Review

I recently submitted an application with Apple to join the Apple Consultants Network. In doing so I knew I had to pass the ACTC certification tests within 45 days of joining. Unfortunately I could not find a testing center in Vancouver so I took the test down in Seattle at Crywolf Training. Gordon Davisson was the proctor and did an amazing job, I showed up 30 mins early and was greeted with donuts and a free review of ML201. Gordon took us thru all the services associated with 10.8 server and gave a couple great tips. (DORA FTW)

The test comprised of 80 multiple choice questions, with two hours on the clock and two crullers in my gut, I began. The first thing I noticed was a lot of the questions would ask “Which is the best sentence to describe blah” and give two correct sentences out of four. This left the tested to choose one answer which they thought was the most applicable, the one that stuck out in my mind most was for the wiki service. Questions with only one possible answer were marked with radio buttons while multi-answer questions had checkboxes. The questions also told the tested how many answers were needed, pick 2, pick 3. The questions themselves were quite simple with exception given to an SSL question and two permissions questions where I had to think, OK do I answer it correctly or the way I think Apple wants me to answer it. To prepare, I used the Amsys Revise IT app to test myself before going in as well as the OS X Server Essentials book by PeachPit.

Do the tests, take screen shots of the questions you’re puzzled by and research those in the PeachPit book, if you do this you’ll be fine.

Zentyal 3.0, Mountain Lion, Kerberos and SSO

Now with Zentyal, you can kerberize your shoes.

This article is a continuation of a really great read by shabangs.net His article is great to bind your Macintosh to a Zentyal directory server however, after completing the how-to I was unable to change a network user’s password, store a local copy of the network user’s password for “mobility” nor leverage some great single sign on services from zentyal.

What we will attempt is to configure /etc/krb5.conf for Mac OS X 10.8, Mountain Lion, so that we will receive a TGT from zentyal when the user either logs in or wakes the computer from sleep.

First you need to get the kerberos realm. To do this sign into Zentyal and go to Users and Groups. In here you’re looking for the LDAP search base, this base will also be your Kerberos realm.

Now we want to search and replace EXAMPLE.COM with that realm, and replace your.server.example.com with the FQDN of your Zentyal server. Only set the dns_lookup_* values to true if you’re using the Zentyal server for DNS.

All edits are client side ONLY
If /etc/krb5.conf does not exist then just create it.

[libdefaults]
default_realm = EXAMPLE.COM
dns_lookup_kdc = true
dns_lookup_realm = true
default_tgs_enctypes = arcfour-hmac-md5 des-cbc-md5 dec-cbc-crc
default_tkt_enctypes = arcfour-hmac-md5 des-cbc-md5 dec-cbc-crc
preferred_enctypes = arcfour-hmac-md5 des-cbc-md5 dec-cbc-crc

[kadmin]
default_keys = des-cbc-crc:pw-salt des-cbc-md5:pw-salt arcfour-hmac-md5:pw-salt aes256-cts-hmac-sha1-96:pw-salt aes128-cts-hmac-sha1-96:pw-salt

In order to obtain a Ticket Granting Ticket (TGT) when logging in via the login window, edit /etc/pam.d/authorization and append default_principal option to the pam_krb5.so line.


auth optional pam_krb5.so use_first_pass use_kcminit default_principal


In order to obtain a Ticket Granting Ticket (TGT) when authenticating to the Screen Saver, edit /etc/pam.d/screensaver and append default_principal option to the pam_krb5.so line.


auth optional pam_krb5.so use_first_pass use_kcminit default_principal


Now sign out and back in as a network user, open a terminal and type klist You should get something like:


lisa:~ test$ klist
Credentials cache: API:51104:6
Principal: test@EXAMPLE.COM

Issued Expires Principal
Mar 2 09:28:04 Mar 2 19:28:04 krbtgt/EXAMPLE.COM@EXAMPLE.COM


If so, great! This means kerberos is running, now try to change the user’s Open Directory password. It should succeed as well. If not make sure you have the console open to see what’s going on. 99% of the time it’s a DNS issue or the clocks on your workstation is out of sync with Zentyal.

Now try to mount an SMB volume from the Zentyal server, it *should* mount without credentials and a new ticket will appear in the output of klist


Issued Expires Principal
Mar 2 09:34:52 Mar 2 19:34:48 krbtgt/EXAMPLE.COM@EXAMPLE.COM
Mar 2 09:34:56 Mar 2 19:34:48 cifs/your.server.example.com@EXAMPLE.COM