Commit graph

51 commits

Author SHA1 Message Date
Andrei Otcheretianski
694a1c6873 SAE: Make sme_sae_auth() return IE offset
Authentication frames include several fixed body parts (see Table 9-68
(Authentication frame body) and Table 9-69 (Presence of fields and
elements in Authentication frames) in IEEE P802.11-REVme/D2.0).

To be able to parse the IE part, these fields need to be skipped. Since
SAE logic already implements this parsing, change SAE authentication
handling functions to return the offset to the IE part. This preparation
is needed for future MLD patches that need to parse out the ML related
elements in the Authentication frames.

Signed-off-by: Andrei Otcheretianski <andrei.otcheretianski@intel.com>
2022-12-17 17:11:16 +02:00
Jouni Malinen
f70db167ab SAE: Derive a variable length PMK with the new AKM suites
Select the PMK length based on the used group (prime length) when using
the new AKM suites for SAE.

Signed-off-by: Jouni Malinen <quic_jouni@quicinc.com>
2022-07-25 00:31:51 +03:00
Jouni Malinen
91010e6f67 SAE: Indicate AKM suite selector in commit for new AKM suites
SAE authentication needs to known which AKM suite is being used to be
able to determine the correct PMK length for the new AKM suite selectors
that use variable length keys.

Signed-off-by: Jouni Malinen <quic_jouni@quicinc.com>
2022-07-25 00:31:51 +03:00
Jouni Malinen
f8eed2e8b8 SAE: Store PMK length and AKM in SAE data
These are needed to be able to support new AKM suites with variable
length PMK.

Signed-off-by: Jouni Malinen <quic_jouni@quicinc.com>
2022-07-25 00:31:51 +03:00
Jouni Malinen
663e190b72 SAE: Remove now unused password identifier argument from non-H2E case
IEEE Std 802.11-2020 mandates H2E to be used whenever an SAE password
identifier is used. While this was already covered in the
implementation, the sae_prepare_commit() function still included an
argument for specifying the password identifier since that was used in
an old test vector. Now that that test vector has been updated, there is
no more need for this argument anymore. Simplify the older non-H2E case
to not pass through a pointer to the (not really used) password
identifier.

Signed-off-by: Jouni Malinen <jouni@codeaurora.org>
2021-04-10 12:12:54 +03:00
Jouni Malinen
0a9d7b169e SAE-PK: Update design for fingerprint encoding into password
Update the SAE-PK implementation to match the changes in the protocol
design:
- allow only Sec values 3 and 5 and encode this as a single bit field
  with multiple copies
- add a checksum character

Signed-off-by: Jouni Malinen <jouni@codeaurora.org>
2020-08-05 22:05:20 +03:00
Jouni Malinen
363dbf1ece SAE-PK: Remove requirement of SAE group matching SAE-PK (K_AP) group
This was clarified in the draft specification to not be a mandatory
requirement for the AP and STA to enforce, i.e., matching security level
is a recommendation for AP configuration rather than a protocol
requirement.

Signed-off-by: Jouni Malinen <jouni@codeaurora.org>
2020-06-10 12:46:49 +03:00
Jouni Malinen
4ff0df39eb SAE-PK: Testing functionality to allow behavior overrides
The new sae_commit_status and sae_pk_omit configuration parameters and
an extra key at the end of sae_password pk argument can be used to
override SAE-PK behavior for testing purposes.

Signed-off-by: Jouni Malinen <jouni@codeaurora.org>
2020-06-08 15:21:18 +03:00
Jouni Malinen
cc22fb1b86 SAE: Move H2E and PK flags to main sae_data
This maintains knowledge of whether H2E or PK was used as part of the
SAE authentication beyond the removal of temporary state needed during
that authentication. This makes it easier to use information about which
kind of SAE authentication was used at higher layer functionality.

Signed-off-by: Jouni Malinen <jouni@codeaurora.org>
2020-06-06 15:18:13 +03:00
Jouni Malinen
6b9e99e571 SAE-PK: Extend SAE functionality for AP validation
This adds core SAE functionality for a new mode of using SAE with a
specially constructed password that contains a fingerprint for an AP
public key and that public key being used to validate an additional
signature in SAE confirm from the AP.

Signed-off-by: Jouni Malinen <jouni@codeaurora.org>
2020-06-02 23:25:22 +03:00
Jouni Malinen
10223b501b SAE: Expose sae_write_commit() error cases to callers
Check whether an error is reported from any of the functions that could
in theory fail and if so, do not proceed with the partially filled SAE
commit buffer.

Signed-off-by: Jouni Malinen <j@w1.fi>
2020-03-08 16:59:42 +02:00
Jouni Malinen
8f8473cebb SAE: Fix peer-commit-scalar reuse check
Only one peer-commit-scalar value was stored for a specific STA (i.e.,
one per MAC address) and that value got replaced when the next SAE
Authentication exchange was started. This ended up breaking the check
against re-use of peer-commit-scalar from an Accepted instance when
anti-clogging token was requested. The first SAE commit message (the one
without anti-clogging token) ended up overwriting the cached
peer-commit-scalar value while leaving that instance in Accepted state.
The second SAE commit message (with anti-clogging token) added ended up
getting rejected if it used the same value again (and re-use is expected
in this particular case where the value was not used in Accepted
instance).

Fix this by using a separate pointer for storing the peer-commit-scalar
value that was used in an Accepted instance. There is no need to
allocate memory for two values, i.e., it is sufficient to maintain
separate pointers to the value and move the stored value to the special
Accepted state pointer when moving to the Accepted state.

This fixes issues where a peer STA ends up running back-to-back SAE
authentication within couple of seconds, i.e., without hostapd timing
out the STA entry for a case where anti-clogging token is required.

Signed-off-by: Jouni Malinen <jouni@codeaurora.org>
2020-02-08 07:19:53 +02:00
Jouni Malinen
cf84246ebb SAE: Add Rejected Groups element into H2E Commit
Signed-off-by: Jouni Malinen <jouni@codeaurora.org>
2019-10-15 15:39:22 +03:00
Jouni Malinen
efd4285299 SAE: Hash algorithm selection for H2E KCK/CN()
Signed-off-by: Jouni Malinen <jouni@codeaurora.org>
2019-10-15 15:39:19 +03:00
Jouni Malinen
aeb022f8e5 SAE: Implement hash-to-element PT/PWE crypto routines
Signed-off-by: Jouni Malinen <jouni@codeaurora.org>
2019-10-15 15:01:53 +03:00
Jouni Malinen
ecd7114072 SAE: Parse Rejected Groups element from H2E SAE commit
Signed-off-by: Jouni Malinen <jouni@codeaurora.org>
2019-10-14 19:38:41 +03:00
Jouni Malinen
86f6084862 SAE: Tell sae_parse_commit() whether H2E is used
This will be needed to help parsing the received SAE commit.

Signed-off-by: Jouni Malinen <jouni@codeaurora.org>
2019-10-14 19:38:41 +03:00
Jouni Malinen
ac734a342e SAE: Fix KCK, PMK, and PMKID derivation for groups 22, 23, 24
IEEE Std 802.11-2016 is not exactly clear on the encoding of the bit
string that is needed for KCK, PMK, and PMKID derivation, but it seems
to make most sense to encode the (commit-scalar + peer-commit-scalar)
mod r part as a bit string by zero padding it from left to the length of
the order (in full octets).

The previous implementation used the length of the prime (in full
octets). This would work for KCK/PMK, but this results in deriving all
zero PMKIDs for the groups where the size of the order is smaller than
the size of the prime. This is the case for groups 22, 23, and 24.
However, those groups have been marked as being unsuitable for use with
SAE, so this fix should not really have a practical impact anymore.
Anyway, better fix it and document this clearly in the implementation
taken into account the unclarity of the standard in this area.

Signed-off-by: Jouni Malinen <j@w1.fi>
2019-08-03 17:00:39 +03:00
Jouni Malinen
fd83089120 SAE: Reuse previously generated PWE on a retry with the same AP
Do not start SAE authentication from scratch when the AP requests
anti-clogging token to be used. Instead, use the previously generated
PWE as-is if the retry is for the same AP and the same group. This saves
unnecessary processing on the station side in case the AP is under heavy
SAE authentiation load.

Signed-off-by: Jouni Malinen <jouni@codeaurora.org>
2019-03-06 13:07:11 +02:00
Jouni Malinen
b0e91e3877 SAE: VLAN assignment based on SAE Password Identifier
The new sae_password parameter [|vlanid=<VLAN ID>] can now be used to
assign stations to a specific VLAN based on which SAE Password
Identifier they use. This is similar to the WPA2-Enterprise case where
the RADIUS server can assign stations to different VLANs and the
WPA2-Personal case where vlanid parameter in wpa_psk_file is used.

Signed-off-by: Jouni Malinen <j@w1.fi>
2019-02-17 17:24:23 +02:00
Jouni Malinen
9be19d0b9c SAE: Add support for using the optional Password Identifier
This extends the SAE implementation in both infrastructure and mesh BSS
cases to allow an optional Password Identifier to be used. This uses the
mechanism added in P802.11REVmd/D1.0. The Password Identifier is
configured in a wpa_supplicant network profile as a new string parameter
sae_password_id. In hostapd configuration, the existing sae_password
parameter has been extended to allow the password identifier (and also a
peer MAC address) to be set. In addition, multiple sae_password entries
can now be provided to hostapd to allow multiple per-peer and
per-identifier passwords to be set.

Signed-off-by: Jouni Malinen <jouni@codeaurora.org>
2018-05-19 17:30:29 +03:00
Jouni Malinen
abcbd0604c SAE: Add Rc variable and peer send-confirm validation
This implements the behavior described in IEEE Std 802.11-2016,
12.4.8.6.6 (Protocol instance behavior - Accepted state) to silently
discard received Confirm message in the Accepted state if the new
message does not use an incremented send-confirm value or if the special
2^16-1 value is used. This avoids unnecessary processing of
retransmitted Confirm messages.

Signed-off-by: Jouni Malinen <j@w1.fi>
2017-12-27 12:19:08 +02:00
Jouni Malinen
9249afc8e1 SAE: Print state changes in debug log
This makes it easier to follow state changes in SAE protocol instances.

Signed-off-by: Jouni Malinen <j@w1.fi>
2017-12-27 00:07:42 +02:00
Jouni Malinen
d8b841eba8 SAE: Make dot11RSNASAESync configurable
The new hostapd.conf parameter sae_sync (default: 5) can now be used to
configure the dot11RSNASAESync value to specify the maximum number of
synchronization errors that are allowed to happen prior to
disassociation of the offending SAE peer.

Signed-off-by: Jouni Malinen <j@w1.fi>
2017-12-26 12:46:22 +02:00
Bob Copeland
6c33eed3ee mesh: Fix PMKID to match the standard
IEEE Std 802.11-2012 11.3.5.4 specifies the PMKID for SAE-derived keys
as:

   L((commit-scalar + peer-commit-scalar) mod r, 0, 128)

This is already calculated in the SAE code when the PMK is derived, but
not saved anywhere. Later, when generating the PMKID for plink action
frames, the definition for PMKID from 11.6.1.3 is incorrectly used.
Correct this by saving the PMKID when the key is generated and use it
subsequently.

Signed-off-by: Bob Copeland <me@bobcopeland.com>
2015-12-28 17:21:08 +02:00
Jouni Malinen
6a58444d27 SAE: Verify that own/peer commit-scalar and COMMIT-ELEMENT are different
This check explicitly for reflection attack and stops authentication
immediately if that is detected instead of continuing to the following
4-way handshake that would fail due to the attacker not knowing the key
from the SAE exchange.

Signed-off-by: Jouni Malinen <j@w1.fi>
2015-06-23 23:10:36 +03:00
Bob Copeland
f3b8ad4d78 SAE: Implement retransmission timer
Add the t0 retransmission timer as specified by IEEE Std 802.11-2012,
11.3.8.4. This makes SAE much more likely to succeed in the case of lost
frames.

Signed-off-by: Bob Copeland <me@bobcopeland.com>
2015-01-10 17:35:52 +02:00
Masashi Honma
a959a3b69d SAE: Fix Anti-Clogging Token request frame format
This commit inserts Finite Cyclic Group to Anti-Clogging Token request
frame because IEEE Std 802.11-2012, Table 8-29 says "Finite Cyclic Group
is present if Status is zero or 76".

Signed-off-by: Masashi Honma <masashi.honma@gmail.com>
2014-11-25 16:08:53 +02:00
Masashi Honma
872b754512 mesh: Fix SAE anti-clogging functionality for mesh
The mesh anti-clogging functionality is implemented partially. This
patch fixes to parse anti-clogging request frame and use anti-clogging
token.

Signed-off-by: Masashi Honma <masashi.honma@gmail.com>
2014-11-25 15:33:04 +02:00
Jouni Malinen
0ef29e0c0b SAE: Move temporary data into a separate data structure
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>
2013-01-12 17:51:54 +02:00
Jouni Malinen
b4fd3613d3 SAE: Free temporary buffers when moving to Accepted state
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>
2013-01-12 17:51:54 +02:00
Jouni Malinen
ce4479c106 SAE: Store commit elements as EC point or bignum instead of octet string
This avoids unnecessary EC point and bignum initialization steps during
the SAE exchange.

Signed-hostap: Jouni Malinen <j@w1.fi>
2013-01-12 17:51:54 +02:00
Jouni Malinen
b0f6124c1c SAE: Store commit scalars as bignum instead of octet string
This avoids unnecessary bignum initialization steps during the SAE
exchange.

Signed-hostap: Jouni Malinen <j@w1.fi>
2013-01-12 17:51:54 +02:00
Jouni Malinen
4df61ba5b9 SAE: Store PWE as EC point or bignum instead of octet string
This avoids unnecessary EC point and bignum initialization steps during
the SAE exchange.

Signed-hostap: Jouni Malinen <j@w1.fi>
2013-01-12 17:51:54 +02:00
Jouni Malinen
629c56d70a SAE: Store rand value as bignum instead of octet string
This avoids unnecessary bignum initialization steps during the SAE
exchange.

Signed-hostap: Jouni Malinen <j@w1.fi>
2013-01-12 17:51:54 +02:00
Jouni Malinen
bf4f5d6570 SAE: Add support for FFC groups that do not use a safe prime
This allows DH groups 22, 23, 24 to be used with SAE.

Signed-hostap: Jouni Malinen <j@w1.fi>
2013-01-12 17:51:54 +02:00
Jouni Malinen
fbfb0e65bf SAE: Add support for FFC groups
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>
2013-01-12 17:51:54 +02:00
Jouni Malinen
388f535461 SAE: Maintain bignum of group order and prime in context data
This simplifies operations by not having to create bignum instances
multiple times during SAE exchange.

Signed-hostap: Jouni Malinen <j@w1.fi>
2013-01-12 17:51:54 +02:00
Jouni Malinen
625f202a74 SAE: Allow enabled groups to be configured
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>
2013-01-12 17:51:53 +02:00
Jouni Malinen
cd9c2714e7 SAE: Add support for ECC group 21 (521-bit random ECP group)
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>
2013-01-12 17:51:53 +02:00
Jouni Malinen
bf14657b9f SAE: Add support for additional ECC groups
In addition to the mandatory group 19 (256-bit random ECP group) add
support for groups 20 (384-bit), 25 (192-bit), and 26 (224-bit).

Signed-hostap: Jouni Malinen <j@w1.fi>
2013-01-12 17:51:53 +02:00
Jouni Malinen
4925b303db SAE: Use defines for key lengths
Signed-hostap: Jouni Malinen <j@w1.fi>
2013-01-12 17:51:53 +02:00
Jouni Malinen
7babd2539c SAE: Add a define for maximum supported prime length
This can be used to increase buffer sizes when adding support for new
groups.

Signed-hostap: Jouni Malinen <j@w1.fi>
2013-01-12 17:51:53 +02:00
Jouni Malinen
a46d72d7d7 SAE: Maintain EC group context in struct sae_data
This can be used to share same EC group context through the SAE
exchange.

Signed-hostap: Jouni Malinen <j@w1.fi>
2013-01-12 17:51:52 +02:00
Jouni Malinen
d136c376f2 SAE: Add support for Anti-Clogging mechanism
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>
2013-01-12 17:51:52 +02:00
Jouni Malinen
dd43026a19 SAE: Rename state variables to match IEEE 802.11 standard
The enum values for struct sae_data::state now match the protocol
instance states as defined in IEEE Std 802.11-2012, 11.3.8.2.2

Signed-hostap: Jouni Malinen <j@w1.fi>
2013-01-12 17:51:52 +02:00
Jouni Malinen
f2e9818f73 SAE: Add processing of the confirm message
This adds validation of the received confirm messages for SAE.

Signed-hostap: Jouni Malinen <j@w1.fi>
2013-01-12 17:51:52 +02:00
Jouni Malinen
fb8fcc2950 SAE: Add generation of the confirm message fields
Signed-hostap: Jouni Malinen <j@w1.fi>
2013-01-12 17:51:52 +02:00
Jouni Malinen
146f6c9a00 SAE: Add processing of the commit message
This adds validation of the received commit messages and key derivation
for SAE.

Signed-hostap: Jouni Malinen <j@w1.fi>
2013-01-12 17:51:52 +02:00
Jouni Malinen
8e31e9550a SAE: Add generation of the commit message fields
This adds derivation of PWE and the needed commit values so that the
full SAE commit message can be built.

Signed-hostap: Jouni Malinen <j@w1.fi>
2013-01-12 17:51:52 +02:00