This is used to get arbitrary information out of the EAP method. Needed
for EAP-WSC to signal credential information obtained from the peer.
Other uses include signaling why EAP-WSC failed (e.g. invalid PIN, etc)
and processing of M2D discovery messages. The information in M2Ds might
be useful to external clients.
We used to open a socket for each wireless interface. This patch uses a
single socket with an attached BPF to handle all EAPoL traffic via a
single file descriptor.
When parsing the EAPoL-Key key data field we don't strip the 0xdd /
0x00 padding from the decrypted data so there may be trailing padding
after the IE sequence and valgrind will report an invalid read of the
length byte. Same thing may happen if we're sent garbage.
When we send M5 & M7, we need to generate a random IV. For testing
purposes, the IV can be provided in settings, otherwise it will be
generated randomly.
We need quite a bit of attributes of M2 for the duration of the WSC
handshake. Most importantly, we need to use the peer's public key when
processing M4 and M6. RegistrarNonce is also needed for generating any
ACK/NACK messages as needed.
Also, peer's device attributes such as Model, Manufacturer, etc might be
useful to report upon successful handshake.
AuthKey is already uploaded into auth_key_hmac. KeyWrapKey is now
uploaded into the AES-CBC(128) cipher. We currently have no use for
EMSK.
So we no longer need to keep the wsc_session_key structure around.
Encrypted Settings TLVs are structured similarly to the various WSC
messages. However, they lack a version2 extension field and use a Key
Wrap Authenticator element instead of Authenticator.
