Why is WPA-encrypted ad-hoc mode disabled in 12.04?

Question

Or, alternatively, how can I check that some WiFi chip supports WPA-encrypted hotspot creation? Is it hardware-dependent? Is anyone able to create WPA-encrypted hotspot?

Update: See the discussion at http://chat.stackexchange.com/transcript/3874

Related bug reports:

https://bugs.launchpad.net/ubuntu/+source/network-manager/+bug/905748

https://bugzilla.gnome.org/show_bug.cgi?id=654772

Solution

Both the SIOCSIWENCODEEXT and SIOCSIWGENIE errors are usually intimately associated with WPA/wpa_supplicant failure.

Have you tried recompiling the latest RT2790 driver with *wpa_supplicant* support enabled -- by default it's NOT!. Also, note that it only supports WPA PSK for adhoc (see line 280 of README_STA below)

1. Get the latest driver, download, extract, cd to the directory.

2. Inside os/linux/config.mk, find lines 10-14, which read:

   
   # Support Wpa_Supplicant
   HAS_WPA_SUPPLICANT=n
   # Support Native WpaSupplicant for Network Maganger
   HAS_NATIVE_WPA_SUPPLICANT_SUPPORT=n
   

3. Change the n at the end of both those lines to y.

4. make and sudo make install the driver (you'll need kernel headers, etc - comment if you need more info on the process).

Reboot, and see if things are any different (errors, etc.) with WPA adhoc.

If not:

1. Following the README_STA file in the extracted directory, copy it cp RT2860STA.dat /etc/Wireless/RT2860STA/RT2860STA.dat

2. Open that file, and change:

   • NetworkType=Adhoc
   • Authmode=WPANONE : important only this (WPA PSK) is supported for adhoc
   • Try EncrypType=NONE (and even TKIP and AES, because README does not say which is supported for adhoc)
   • Set WPAPSK to the key -- ***wpa_supplicant* may not be fully supported in adhoc*

3. Unload/load the the module to make it take effect: rmmod and modprobe, respectively.

4. See the README_STA file for more parameters and details, and try experimenting. Comment if you need more help.

Comments

[Lucio]

"how can I check that some WiFi chip supports WPA" with your model device. "Is it hardware-dependent?" There is many router that doesn't but there is an algorithmic (TKIP) that solve that compatibility problem.

[int_ua]

Notice: I'm talking about Ubuntu in a hotspot mode, not about routers

[Thomas Ward]

As an aside, this may be a kernel incompatiblity problem, as the GNOME bug tracker here suggests that newer kernels do not work with WPA / WPA2 on Ad-Hoc networks.

[int_ua]

Why NONE? Can we use TKIP for example? Trying this.

[int_ua]

And it creates open adhoc network, no encryption at all.

[pl1nk]

@int_ua : Just to clarify, have you tried this and you resulted with an open adhoc network?

[int_ua]

Yes, I've copied the config adding only new lines where they should be and changing the password and executed the wpa_supplicant command with sudo. It showed a couple of ioctl[SIOCSIWENCODEEXT]: Invalid argument and the network is showed as non-encrypted on Nokia N900. The output: paste.ubuntu.com/1059026

[int_ua]

Unfortunately, I'm out of town with a very limited GPRS traffic, can't check the solution right now. Also, I was asking a generic question, I don't really like your edits since all notebooks with 12.04 I've met wasn't being able to create WPA-encrypted hotspot. And that's a big issue that should not be split into hardware-specific discussions.