Since the fall of 2008, there have been two wireless networks on campus. One network, called VT-Wireless, encrypts all traffic and is secured with EAP-TLS or PEAP-MSCHAPv2. The other network, VT_WLAN, is an unencrypted, captive portal wireless network. While connections to VT-Wireless are secure by default, and require no user authentication once set up, the EAP-TLS setup has a number of steps. In contrast, setup for VT_WLAN network is negligible, but you will be required to manually authenticate each time you connect (although this can be scripted), and your traffic will be readable to everyone.

Select a connection method

Network	Authentication	Encrypted	Setup	Support
VT-Wireless	Strong, two way (EAP-TLS)	Yes	Involved	Many devices (Laptops and Android devices)
VT-Wireless	Good (PEAP-MSCHAPv2)	Yes	Simple	Most devices
VT_WLAN	Weak (Captive portal)	No	Negligible	All devices

The best option is EAP-TLS, which provides strong, two-way authentication to ensure that neither you or the authentication server can be impersonated. Unfortunately, setting up EAP-TLS can be someonewhat involved because it requires a certificate to be installed on the device. If this is a problem, you should try PEAP-MSCHAPv2 as it still provides somewhat strong authentication and allows connection to the encrypted VT-Wireless network.

VT_WLAN is an unsecure captive portal wireless network. It requires no set up at all, but you must log in with your PID and password every time you connect. Since it is not secure, it is simple for any and all unencrypted traffic on the network to be sniffed by anyone within range and is also vulnerable to deauthentication attacks. Its use is strongly discourage.

Select a method for setup instructions
EAP-TLS	PEAP-MSCHAPv2

Historical EAP-TLS Configuration

Note: This section of this article has been archived and may be out of date; please see the EAP-TLS page for updated instructions. It is preserved here at least for time being for those connecting using older versions of NetworkManager or using Wicd.

The setup for EAP-TLS involves downloading a passworded personal certificate and making sure a copy of the certificate authority's signing certificate is on your computer. Some network managers, such as NetworkManager, require an extra step of converting the personal certificate to a different format.

Obtaining the VT-Wireless Certificate

Regardless of what program you use to make your connection, you will need to obtain your p12 certificate and password from CNS. Complete the form and download the p12 certificate file. Save the certificate password permanently and copy it for immediate use. You will need it in setting up your connection to VT-Wireless.

Checking for the CA Certificate

Next, you will need to make sure you have the Thawte Premium Server Certificate Authority (CA) certificate. In Ubuntu, you should be able to find this certificate at /etc/ssl/certs/Thawte_Premium_Server_CA.pem. If you can't find the certificate on your system, you can copy the text below and paste it into a new file of the same name.

Choosing a Network Manager

NetworkManager is installed by default on Ubuntu and Fedora. As of fall 2009, NetworkManager does not support the PKCS#12 format certificates that CNS provide out of the box. For Android devices running 2.2 and newer, please refer to the Android EAP-TLS instructions. Android's network manager does not need the certificate to be converted. Converting the certificate requires some work, but the steps are outlined below. If you don't rely on NetworkManager for other kinds of connections like mobile broadband or VPN, or are having problems with NetworkManager, use Wicd as a graphical connection manager instead. If you don't want or need a graphical interface, a WPA Supplicant configuration is also described below.

Connecting by NetworkManager

The setup for NetworkManager depends on your version of the software. Please follow the instructions appropriate to your version below. In GNOME, you can right-click the NetworkManager applet icon in the panel and select "About" to find the version of NetworkManager.

Ubuntu users: Version 0.6 ships with 8.04 Hardy Heron, 0.7 ships with 8.10 Intrepid Ibex and 9.04 Jaunty Jackalope, and 0.8 ships with 9.10 Karmic Koala.

NetworkManager 0.7 and 0.8

Converting the certificate to PEM certificates and keys

NOTE: The following steps are only necessary to use NetworkManager 0.7 and 0.8. NetworkManager 0.6 has a more straightforward setup

You will need to convert the PKCS#12 (.p12) certificate into PEM formats. We will assume your downloaded p12 file is called netcert-1.p12 and that its password is netcertpasswd. Open a terminal and cd to the directory that contains your .p12 file. Then issue the following commands:

openssl pkcs12 -in netcert-1.p12 -out vt_client_cert.pem -clcerts -nokeys
openssl pkcs12 -in netcert-1.p12 -out vt_private_key.pem -nocerts

In each step, you will be prompted for the password (netcertpasswd) that you were issued along with your .p12 certificate. Right click and paste it in or press ctrl+shift+v if you're using the GNOME Terminal. Additionally, in the final step where you generate your private key, you will be asked to enter a password. Paste in same password.

Sources

WPA2 EAP/TLS Linux client setup

Left-click the NetworkManager applet and select the VT-Wireless network.

You will see a prompt to configure the connection. First, from the Authentication drop-down menu, select TLS.

Next, fill in the rest of the options:

Field	Value
SSID	VT-Wireless
Wireless Security	WPA & WPA2 Enterprise
Authentication	TLS
Identity	Your VT PID
User Certificate	/path/to/vt_client_cert.pem
CA Certificate	/etc/ssl/certs/Thawte_Premium_Server_CA.pem
Private Key	/path/to/vt_private_key.pem
Private Key Password	netcertpasswd

Click "Connect" and you should connect to the VT-Wireless network.

NetworkManager 0.6

Left-click the NetworkManager applet and select VT-Wireless. You will be prompted to enter information about the connection. Here are the entries you should use:

Field	Value
SSID	VT-Wireless
Wireless Security	WPA2 Enterprise
EAP Method	TLS
Key Type	Automatic (Default)
Phase2 Type	None (Default)
Identity	Your VT PID
Password	empty
Client Certificate File	(None)
CA Certificate File	(None)
Private Key File	netcert-1.p12 (the certificate downloaded from VT NetCert)
Private Key Password	netcertpasswd

Connecting with Wicd

The following instructions were written for Wicd 1.7.x on Archlinux and may not work on other platforms or versions. If you would like to see additional coverage, please add it yourself or make a request on the wiki's wanted page.

Wicd is an alternative to NetworkManager. It has proven to be more reliable than NetworkManager for a number of users. Unlike NetworkManager, to use Wicd, you do not need to convert the PKCS#12 certificate that CNS provides to a set of PEM certificates. Also unlike NetworkManager, wicd does not have VPN or mobile-broadband support built in (yet, Q1 2011).

To install Wicd on Debian-based systems, run sudo apt-get install wicd. Installing it will uninstall NetworkManager.

To install wicd on Archlinux, run pacman -S wicd.

Also be sure to comment out any other network-management software you might have in /etc/rc.conf deamons array and add wicd (after dbus).

Before wicd can be used with VT-Wireless, you have to add a new template. These templates are stored in /etc/wicd/encryption/templates/

Here you will want to make a new file, called eap-tls-vt (case is important here)

and paste these contents into the file:

name = EAP-TLS-VT
author =  stanner
version = 1
require identity *Identity private_key *Private_Key private_key_passwd *Private_Key_Password
optional ca_cert *Path_to_CA_Cert 

-----
ctrl_interface=/var/run/wpa_supplicant
network={
   ssid="$_ESSID"
   key_mgmt=WPA-EAP
   eap=TLS
   identity="$_IDENTITY"
   ca_cert="$_CA_CERT"
   private_key="$_PRIVATE_KEY"
   private_key_passwd="$_PRIVATE_KEY_PASSWD"
}

After saving this file, you will want to make sure you add your new template to the "active" list by adding "eap-tls-vt" to the bottom of /etc/wicd/encryption/templates/active

Now restart wicd by either restarting the service or by restarting your system.

Open Wicd, either by left clicking the tray icon or by selecting Applications->Internet->Wicd Network Manager. Allow Wicd to scan the wireless networks then check the "Automatically connect to this network" checkbox by the topmost VT-Wireless entry. (You do not need to check the boxes for every VT-Wireless entry. The screenshot below was made from a working configuration that automatically checked all of them.)

Click the "Properties" button of the topmost VT-Wireless entry and enter the following information:

Check the "Use these settings for all networks sharing this essid" box.
Leave the "Use Encryption" box checked.
Select eap-tls-vt from the encryption type dropdown menu.
Enter your PID into the "Identity" box.
Enter the path to your private key into the "Private Key" box, i.e. /home/user/netcert/netcert-1.p12.
Paste the certificate password into the "Private Key Password" box.
Enter the path to the CA Cert (if you have ca_certificates installed on your system,) /etc/ssl/certs/Thawte_Premium_Server_CA.pem

Click "OK" and your computer should be all setup to use VT-Wireless.

Connecting by WPA Supplicant

WPA Supplicant is the preferred method of connection to WPA-secured wireless networks without a graphical interface. It supports PKCS#12 certificates.

Editing wpa_supplicant.conf

Add the following to your /etc/wpa_supplicant.conf file (if no file exists, create it):

ctrl_interface=/var/run/wpa_supplicant
eapol_version=1
ap_scan=1
fast_reauth=1
network={
    ssid="VT-Wireless"
    key_mgmt=WPA-EAP
    eap=TLS
    identity="PID"
    private_key="/PATH/TO/NETCERT.p12"
    private_key_passwd="PASSWORD"
}

Replace PID with your actual PID (without any trailing @vt.edu), /PATH/TO/NETCERT.p12 with the actual path to your certificate (you can store it in /etc/netcert) and PASSWORD with the certificate password given to you when you downloaded the certificate. Note the certificate used here should be the original PKCS#12 file you downloaded. Reformatting the certificate is only necessary for NetworkManager.

Running WPA Supplicant

Ubuntu

In Ubuntu, make sure to shut down NetworkManager with:

$ sudo /etc/init.d/NetworkManager stop

Next, issue the following command:

$ sudo wpa_supplicant -B -i wlan0 -D wext -c /etc/wpa_supplicant.conf

Confirm that you are associated with VT-Wireless

$ sudo iwconfig INTERFACE

where INTERFACE is your wireless card's device interface. Usually this is wlan0 but depending on udev and perhaps other system features, it might appear as ath0, eth1 or something else. Run sudo ifconfig -a to see all your interfaces listed. If you have properly connected, you should see Access Point: followed by a MAC address (e.g., 00:0F:23:EA:4A:01). If instead you see Access Point: not associated, try the command again. If it still fails after a couple of seconds, bring down the interface and bring it back up:

$ sudo ifconfig INTERFACE down
$ sudo ifconfig INTERFACE up

and re-issue the wpa_supplicant command. Next, obtain an IP address. In Ubuntu, this is done with

$ sudo dhclient INTERFACE

If all goes well, you'll obtain an IP address. Otherwise, you'll receive a timeout for your DHCP request.

Gentoo

If you're already using wpa_supplicant, just restart your interface after editing wpa_supplicant.conf:

# /etc/init.d/wlan0 restart

This should connect you. If you're not using wpa_supplicant, you'll need to migrate from Wireless Tools to it in order to use WPA. Refer to the Gentoo documentation for a step-by-step guide to setting up WPA Supplicant.

Network Information Sources

Linux and Unix Users Group at Virginia Teck Wiki ^β

Virginia Tech Wifi (OLD)

Select a connection method

Contents

Historical EAP-TLS Configuration

Obtaining the VT-Wireless Certificate

Checking for the CA Certificate

Choosing a Network Manager

Connecting by NetworkManager

NetworkManager 0.7 and 0.8

Converting the certificate to PEM certificates and keys

NetworkManager 0.6

Connecting with Wicd

Connecting by WPA Supplicant

Editing wpa_supplicant.conf

Running WPA Supplicant

Ubuntu

Gentoo

Network Information Sources

Linux and Unix Users Group at Virginia Teck Wiki β

Virginia Tech Wifi (OLD)

Select a connection method

Contents

Historical EAP-TLS Configuration

Obtaining the VT-Wireless Certificate

Checking for the CA Certificate

Choosing a Network Manager

Connecting by NetworkManager

NetworkManager 0.7 and 0.8

Converting the certificate to PEM certificates and keys

NetworkManager 0.6

Connecting with Wicd

Connecting by WPA Supplicant

Editing wpa_supplicant.conf

Running WPA Supplicant

Ubuntu

Gentoo

Network Information Sources

Linux and Unix Users Group at Virginia Teck Wiki ^β