These functions provide software encryption support
for 802.11 device drivers.
The
ieee80211_crypto_attach ();
function initializes crypto support for the interface
Fa ifp ,
and sets the initialization vector (IV) for WEP encryption to
a random number derived from a secure PRNG.
The
ieee80211_crypto_detach ();
function frees data structures associated with crypto support
for the interface
Fa ifp .
The
ieee80211_wep_crypt ();
function runs the appropriate WEP encryption algorithm over the 802.11
encapsulated frame held in the mbuf chain
Fa m0 ,
for transmission or reception on the interface
Fa ifp .
The
Fa txflag
argument specifies whether the frame is being received or transmitted.
A value of 0 indicates that the frame is being received and should
therefore be decrypted; a non-zero value indicates that the frame
is being transmitted
and should be encrypted.
IMPLEMENTATION NOTES
The
ieee80211_wep_crypt ();
function stores its IV in the interface's embedded
Vt struct ieee80211com
instance.