Wireless network security
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What is WPA ?
Wi-Fi Protected Access (WPA) is a wireless encryption standard and the successor of Wired Equivalent Privacy (WEP). WPA has been supported since NetBSD 4.0. NetBSD uses wpa_supplicant(8), a cross-platform framework for WPA.
For setting up WPA, create the file /etc/wpa_supplicant.conf and paste following code, replacing your own SSID and Key:
network={
ssid="MYWLAN"
scan_ssid=1
key_mgmt=WPA-PSK
psk="MySecretPassphrase"
}
It's important to set your exact SSID and of course your exact key. Both are case sensitive. For additional parameters in the configuration file, please refer to the manual page wpa_supplicant.conf(5).
For setting WPA up with dhclient(8), make the configuration in rc.conf(5) as follows:
dhclient=YES # Do not wait for lease; useful if no network is within reach, so boot will not hang dhclient_flags="-nw" wpa_supplicant=YES wpa_supplicant_flags="-B -i ath0 -c /etc/wpa_supplicant.conf"
Also, note that wpa_supplicant lives in /usr/sbin. Depending on your file system layout, you may need to add /usr to the critical_filesystems_local override in /etc/rc.conf. Example:
critical_filesystems_local="/var /usr"
That's it. Now you can start wpa_supplicant with /etc/rc.d/wpa_supplicant start, then restart your network with /etc/rc.d/network restart.
Using dhcpcd instead of dhclient
In NetBSD 5.0, you can also put a new line in /etc/ifconfig.ath0 that mentions dhcp:
up dhcp
This will bring the interface up and start dhcpcd(8), the new DHCP client daemon. If you do this, you can remove dhclient from your configuration and change the dhclient_flags to dhcpcd_flags:
# Do not wait for lease; useful if no network is within reach, so boot will not hang dhcpcd_flags="-q -b" wpa_supplicant=YES wpa_supplicant_flags="-B -i ath0 -c /etc/wpa_supplicant.conf"
Adding a new network
With the above setup, all you have to do is add the configuration to your wpa_supplicant.conf and then tell wpa_supplicant to reload its config:
wpa_cli reconfigure
That's it. With
wpa_cli status
you can track the status, and see if it authenticates. If you wait a moment, dhcpcd will pick up the change and automatically obtain a new lease.
If the wpa_cli command generates a "Failed to connect to wpa_supplicant - wpa_ctrl_open: No such file or directory" error, make sure you set the ctrl_interface parameter in the wpa_supplicant.conf(8) as:
ctrl_interface=/var/run/wpa_supplicant ctrl_interface_group=wheel
Other Network Configurations
wpa_supplicant can also connect to other network configurations. These configurations can be given different priorities using the priority field, with a higher number indicating a higher priority.
Unprotected Networks
network={
ssid="MYUNPROTECTEDWLAN"
scan_ssid=1
key_mgmt=NONE
priority=100
}
WEP encryption
WEP is the weakest of current 802.11 encryption solutions. It is known to be completely broken; breaking WEP can be done in mere seconds. However, sometimes there is a need to use WEP in legacy networks. Here is a configuration if you want to do it with wpa_supplicant:
network={
ssid="MYWEAKLYENCRYPTEDWLAN"
key_mgmt=NONE
wep_key0="12345" # or 13 characters, or a hexkey starting with 0x
wep_tx_keyidx=0
}
Oddly enough, the wep_key0 and wep_tx_keyidx seem to be undocumented in wpa_supplicant.conf(5)...
You don't have to use wpa_supplicant to do it, though. With ifconfig you can do it just as easily:
ifconfig ath0 ssid MYWEAKLYENCRYPTEDWLAN nwkey 12345
Password-Authenticated MSCHAPv2
This seems to be a common configuration for password-authenticated networks:
network={
ssid="WLANSSID"
key_mgmt=IEEE8021X
eap=PEAP
phase2="auth=MSCHAPV2"
identity="login"
password="password"
}
WPA2
Step 0: for NetBSD 5.0.1 use wpa_passphrase() to create a basic configuration:
wpa_passphrase My_world My_secret | tee /etc/wpa_supplicant.conf | nl
1 network={
2 ssid="My_world"
3 #psk="My_secret"
4 psk=b7d1304e45ebbdb66ebd458b2d89e6871ac1dcb1efae521beaa76fb78708fe9b
5 }
Step 1: and add the following changes marked by (+)
+ap_scan=1
+ctrl_interface=/var/run/wpa_supplicant
+ctrl_interface_group=0
+
network={
+ scan_ssid=1
+ proto=RSN WPA
+ key_mgmt=WPA-PSK
+ pairwise=CCMP TKIP
+ group=CCMP TKIP
ssid="My_world"
#psk="My_secret"
psk=b7d1304e45ebbdb66ebd458b2d89e6871ac1dcb1efae521beaa76fb78708fe9b
}
+
Step 2: and add the following to ifconfig.INTERFACE_NAME with your own address values
cat -n /etc/ifconfig.wpi0
1 inet 192.168.1.23 netmask 255.255.255.0
2 !route add default 192.168.1.254
Step 3: and add the following to /etc/defaults/rc.conf
fgrep -i wpa /etc/defaults/rc.conf | nl
1 # WPA daemons.
2 wpa_supplicant=YES
3 wpa_supplicant_flags="-B -i wpi0 -c /etc/wpa_supplicant.conf"
