Number of regressions had shown up in wpa_supplicant implementation of
SAE group selection due to different integer array termination (-1 in
hostapd, 0 in wpa_supplicant) being used for SAE groups. The
default_groups list did not seem to use any explicit termination value.
In addition, the sae_group_index was not cleared back to 0 properly
whenever a new SAE session was started.
Signed-hostap: Jouni Malinen <j@w1.fi>
The peer commit element needs to be validated to pass one of the steps
listed in IEEE 802.11, 11.3.5.4:
scalar-op(r, ELEMENT) = 1 modulo p
Similar step was present for ECC groups, but was missing for FFC groups.
This is needed to avoid dictionary attacks.
Thanks to Michael Roßberg and Sascha Grau for reporting this.
Signed-hostap: Jouni Malinen <j@w1.fi>
It is clearer to keep all the validation steps described in IEEE 802.11
11.3.5.4 in a single location instead of splitting this between the
parsing and processing functions.
Signed-hostap: Jouni Malinen <j@w1.fi>
This allows even more memory to be freed when the SAE instance enters
Accepted state. This leaves only the minimal needed memory allocated
during the association which is especially helpful for the AP
implementation where multiple stations may be associated concurrently.
Signed-hostap: Jouni Malinen <j@w1.fi>
Most of the variables are not needed anymore once the SAE instance
has entered Accepted state. Free these to save memory.
Signed-hostap: Jouni Malinen <j@w1.fi>
The rand/mask values and commit scalar are derived using the exact same
operations, so only use a separate function for deriving the commit
element.
Signed-hostap: Jouni Malinen <j@w1.fi>
There is no need to postpone this validation step to a separate
processing operation for the commit message, so move the minimal
validation tasks into the parsing functions.
Signed-hostap: Jouni Malinen <j@w1.fi>
Move the bignum comparison part into the bignum library to allow a
single implementation of rand generation for both ECC and FCC based
groups.
Signed-hostap: Jouni Malinen <j@w1.fi>
This allows FFC groups to be used with SAE. Though, these groups are not
included in the default sae_groups value based on what is available
since the FFC groups have the additional requirement of using a safe
prime with the current implementation (or specification of the group
order).
Signed-hostap: Jouni Malinen <j@w1.fi>
hostapd.conf sae_groups parameter can now be used to limit the set of
groups that the AP allows for SAE. Similarly, sae_groups parameter is
wpa_supplicant.conf can be used to set the preferred order of groups. By
default, all implemented groups are enabled.
Signed-hostap: Jouni Malinen <j@w1.fi>
In addition to the trivial change in adding the new group ientifier,
this required changes to KDF and random number generation to support
cases where the length of the prime in bits is not a multiple of eight.
The binary presentation of the value needs to be shifted so that the
unused most significant bits are the zero padding rather than the extra
bits in the end of the array.
Signed-hostap: Jouni Malinen <j@w1.fi>
The counter>200 check needs to be done before the continue-on-not-found
case to be effective in stopping this loop.
Signed-hostap: Jouni Malinen <j@w1.fi>
The buffer is set based on maximum group prime length, but pwd-value
needs to be correct length for the negotiated group.
Signed-hostap: Jouni Malinen <j@w1.fi>
This makes the SAE implementation a bit simpler by not having to build
the bignum for group order during execution.
Signed-hostap: Jouni Malinen <j@w1.fi>
hostapd can now be configured to use anti-clogging mechanism based on
the new sae_anti_clogging_threshold parameter (which is
dot11RSNASAEAntiCloggingThreshold in the standard). The token is
generated using a temporary key and the peer station's MAC address.
wpa_supplicant will re-try SAE authentication with the token included if
commit message is rejected with a token request.
Signed-hostap: Jouni Malinen <j@w1.fi>
IEEE Std 802.11-2012, 11.3.8.6.1: If there is a protocol instance for
the peer and it is in Authenticated state, the new Commit Message
shall be dropped if the peer-scalar is identical to the one used in
the existing protocol instance.
Signed-hostap: Jouni Malinen <j@w1.fi>
