Aruba Networks FIPS 140-2 manual User Authentication, Wireless Client Authentication

4.1.2 User Authentication

Authentication for the User role depends on the module configuration. When the module is configured as a Mesh AP, the User role is authenticated via the WPA2 preshared key. When the module is configured as a Remote AP, the User role is authenticated via the same IKE pre-shared key/RSA key pair that is used by the Crypto Officer. In CPSec AP mode, User authentication is accomplished via same RSA key pair that is used by the Crypto Officer.

4.1.3 Wireless Client Authentication

The wireless client role, in the Remote AP, Mesh AP or CPSec AP configuration authenticates to the module via WPA2. WEP and/or Open System configurations are not permitted in FIPS mode. In advanced Remote AP configuration, when Remote AP cannot communicate with the controller, the wireless client role authenticates to the module via WPA2-PSK only.

4.1.4 Strength of Authentication Mechanisms

The following table describes the relative strength of each supported authentication mechanism.

Authentication	Mechanism Strength
Mechanism
IKE shared secret	For IKE, there are a 95^8 (=6.63 x 10^15) possible preshared keys. In order
(CO role)
	to test the guessed key, the attacker must complete an IKE aggressive mode
	exchange with the module. IKE aggressive mode consists of a 3 packet
	exchange, but for simplicity, let’s ignore the final packet sent from the AP to
	the attacker.
	An IKE aggressive mode initiator packet with a single transform, using
	Diffie-Hellman group 2, and having an eight character group name has an
	IKE packet size of 256 bytes. Adding the eight byte UDP header and 20 byte
	IP header gives a total size of 284 bytes (2272 bits).
	The response packet is very similar in size, except that it also contains the
	HASH_R payload (an additional 16 bytes), so the total size of the second
	packet is 300 bytes (2400 bits).

Assuming a link speed of 1Gbits/sec (this is the maximum rate supported by the module), this gives a maximum idealized guessing rate of 60,000,000,000

/4,672 = 12,842,466 guesses per minute. This means the odds of guessing a correct key in one minute is less than 12,842,466/(6.63x10^15) = 1.94 x 10^- 9, which is much less than 1 in 10^5.

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