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

Posted: March 27th, 2013 | Author: | Filed under: Mac OS X, Mac OS X Server, Open Directory, RADIUS, VPN | 3 Comments »

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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 yes
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


3 Comments on “Cisco AAA VPN and RADIUS on Mac OS X Server 10.8 – Mountain Lion”

  1. 1 Bryan said at 1:27 am on November 13th, 2013:

    This works, but how do you configure this for allowing various groups access to different servers? Right now your config allows ALL users access to everything which defeats the point of having RADIUS authentication.

  2. 2 jordan said at 10:01 am on November 13th, 2013:

    Hey Bryan,

    Simply create a group in OD called VPN Users or something, add the users to this group and then add the group to the SACL.

    Hope this helps.
    Jordan

  3. 3 Bryan said at 12:48 am on November 15th, 2013:

    Thats only OK if you want to give everyone in any group associated access to every device.

    Say I have 4 sets of router and 3 groups.

    I want group 1 and 3 to have access to router 1

    group 2 and 3 access to router 2

    group 2 access to router 2

    and group 1 and 2 access to router 1

    I am sure this is possible but for some reason it’s not clear to me how to set that up.


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