Hello, 

I'm trying to set up a radius server here in my office to permit WLAN usage, and I 
really feel like I'm coming up against my limits of understanding on the technologies 
involved. 

I've successfully compiled yesterday's CVS release which include EAP-TTLS support, but 
I'm running into some serious issues (most likely due to lack of clue on my part) 
getting it working. The server is a Debian testing install, with openssl compiled 
from source. The base station is a Linksys WRT-54G, although I haven't gotten to 
the point were I think there's a problem there. 

Here's my list of questions:

1. EAP-TTLS is dependent on EAP-TLS, which requires a server cert. So far, I've been 
unable to successfully create a cert that freeradius likes. In the radiusd.conf file, 
there's an certificate_file argument, along with a CA_file argument. My understanding 
of the reason for this is that with EAP-TLS, authentication is done by certs alone - 
the user must have the server cert's public key loaded, and the user must present a 
public key signed by the CA.

But with TTLS, the client cert does not appear to be a requirement. Does that mean I 
can use a self-signed cert and not worry about the CA_file, or do I still need to 
create both? And if so, does anyone have a working openssl recipe to create these? So 
far I've been unsuccessful in creating anything other than a self-signed key.

2. I think I'm missing some understanding when it comes to the differences between 
authentication protocols (pap, mschap, etc) and authentication mechanisms (users file, 
smbpasswd, sql, pam, etc). My ideal scenario is for TTLS to use PAM (which 
authenticates based on md5 hashes in /etc/shadow), allowing anyone with an account on 
the 
server running radiusd to connect to the WLAN, but I'm not quite sure how the auth 
protocol interacts with auth-types. I have "DEFAULT Auth-Type := Pam" in my users 
file; 
do I need to do anything further depending on the auth protocol I use "inside" the 
ESP-TTLS tunnel (pap, chap, etc)?

3. I'm really, really in the dark when it comes to the key distribution mechanism. 
with 
EAP-TTLS and WPA, what system actually generates and distributes the WPA key? Does the 
radius server handle that, or does it only negotate access and let the base station 
generate a random key? Is there a knob in the config I need to set up for this?

Thank you in advance for your patience. I'm sure I'll have more questions later.

Thanks,

-Chris

- 
List info/subscribe/unsubscribe? See http://www.freeradius.org/list/users.html

Reply via email to