Trying to connect to network with LEAP authentication
Jouni Malinen
jkmaline
Thu Sep 28 18:31:03 PDT 2006
On Thu, Sep 28, 2006 at 08:11:57AM -0400, Dan Williams wrote:
> On Wed, 2006-09-27 at 20:08 -0700, Jouni Malinen wrote:
> I'm still somewhat unclear here... Given a card like airo or ipwXXXX,
> what parts of the connection process does the firmware handle, does the
> driver handle, and does wpa_supplicant handle? On an airo, it's _all_
> firmware of course, using private ioctl() calls. On the ipw2x00
> drivers, you can set the auth alg to LEAP, but it seems the firmware
> handles the rest? I see a lot of LEAP code (eap-leap.c) in
> wpa_supplicant, but what's the handling flow?
I don't know what airo driver/firmware is doing, but with ipw and Host
AP drivers, the tasks are done as follows:
- wpa_supplicant configures driver to use Network EAP as the
authentication algorithm
- driver/firmware sends out IEEE 802.11 management/authentication frame
with auth alg set to 0x80 (Network EAP); AP replies to this
- driver/firmware sends out IEEE 802.11 association request; AP replies
to this
- driver reports association as wireless event
- wpa_supplicant starts IEEE 802.1X/EAP authentication by sending out
EAPOL-Start frame; AP/Authenticator is likely to also start by sending
out EAP-Request/Identity; anyway, this identity request is sent out
either automatically or as a response to EAPOL-Start
- wpa_supplicant replies with EAP-Response/Identity
- AP/Authenticator starts LEAP authentication
- wpa_supplicant completes LEAP authentication with the authenticator
- AP/Authenticator sends WEP keys (or does WPA/WPA2 4-way handshake)
using EAPOL-Key frames
- wpa_supplicant parses the EAPOL-Key frames and configures dynamic
encryption keys to the driver
- driver/firmware takes care of encrypting/decrypting data frames
--
Jouni Malinen PGP id EFC895FA
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