Key exchange with LEAP

[marjus]

When using LEAP, how does the RADIUS server tell the client which key to use for encryption? Is the key transmitted wireless to the client? If so, is the key encrypted and with wich key?

[p.krane]

Here’s some reference URL’s you should go through:

http://www.cisco.com/warp/public/102/wlan/draft-ietf-radius-ext-07.txt

http://www.cisco.com/warp/public/102/wlan/nextgen.html#ref33Hope this helps.

[marjus]

Than you but that was not quite what I was looking for.

After the mutual authentication, the client derrives a session key, which can be rotated e.g. every 15 minutes. But how does the client derrive the session key?

I know that the key is NOT sent int the clear throught the air.

[shaun.oliver]

The session WEP key and broadcast WEP key are transmitted during authentication.

The broadcast WEP key is encrypted with the session WEP key.

The session WEP key is encrypted, although I can't recall the exact method. There might be some details on CCO, or check the EAP specifications.