The MIC length depends on the negotiated group when SAE-EXT-KEY or OWE
key_mgmt is used. wlantest can determine the group if the capture file
includes the group negotiation, i.e., the initial association when a PMK
was created. However, if the capture file includes only an association
using PMKSA caching, the group information is not available. This can
result in inability to be able to process the EAPOL-Key frames (e.g.,
with the "Truncated EAPOL-Key from" message).
If the negotiated group is not known and an EAPOL-Key frame length does
not seem to match the default expectations for group 19, check whether
the alternative lengths for group 20 or 21 would result in a frame that
seems to have valid length. If so, update the STA entry with the guessed
group and continue processing the EAPOL-Key frames based on this.
Signed-off-by: Jouni Malinen <quic_jouni@quicinc.com>