This commit adds a new wrapper, random_get_bytes(), that is currently
defined to use os_get_random() as is. The places using
random_get_bytes() depend on the returned value being strong random
number, i.e., something that is infeasible for external device to
figure out. These values are used either directly as a key or as
nonces/challenges that are used as input for key derivation or
authentication.
The remaining direct uses of os_get_random() do not need as strong
random numbers to function correctly.
ap_setup_locked=2 can now be used to enable a special mode where
WPS ER can learn the current AP settings, but cannot change then.
In other words, the protocol is allowed to continue past M2, but
is stopped at M7 when AP is in this mode. WPS IE does not
advertise AP Setup Locked in this case to avoid interoperability
issues.
In wpa_supplicant, use ap_setup_locked=2 by default. Since the AP PIN
is disabled by default, this does not enable any new functionality
automatically. To allow the read-only ER to go through the protocol,
wps_ap_pin command needs to be used to enable the AP PIN.
When multiple wireless interfaces are used with WPS, the UPnP
subscriptions need to be removed whenever a matching Registrar
instance gets removed. This avoids a segfault due to access to
freed memory during hostapd shutdown.
In addition, the UPnP interface instance structure needs to be
freed to avoid memory leak.
WPS external Registrars can get confused about multiple UPnP
instances (one per radio) on a dual-concurrent APs. Simplify the
design by sharing a single UPnP state machine for all wireless
interfaces controlled by hostapd. This matches with the previous
changes that made a single command enable WPS functionality on
all interfaces.
This is relatively minimal change to address the sharing of the
state among multiple struct hostapd_data instances. More cleanup
can be done separately to remove unnecessary copies of information.
This is needed to avoid issues with APs that restart their UPnP,
e.g., when ER reconfigures them. The previously known settings are
now cached and taken into use if an AP is detected to leave
(ssdp:byebye) and then return.
Verify that the UUID given to wps_er_pbc command is known and only
activate PBC mode on the matching AP. The UUID can be that of the
AP or the station/Enrollee.
This command can be used to enroll a network based on a local
network configuration block instead of having to (re-)learn the
current AP settings with wps_er_learn.
UPnP event subscriptions are not supposed to be dropped based on
whether events can be delivered quickly enough. Leave dropping to
happen only based on failed deliveries to avoid issues with a burst
of events kicking out still active subscribers.
Do not send more than five Probe Request WLANEvent notifications
per second. Even though the limit should in theory apply to all
WLANEvents, it is better not to drop EAP notifications because
of Probe Request frames and really, the only real reason for
event bursts is Probe Request frames.
Instead of queuing all events for a subscriber, only queue more
important events if delivery of event notifications starts failing.
This allows more time for the subscriber to recover since the maximum
queue length if not reached because of Probe Request frames only.
Instead of dropping the subscription on first failure, allow up to
10 failures before dropping. In addition, drop the callback URLs
one by one instead of full subscription if only one URL is failing.
This makes it easier to figure out what could have failed in the
WPS protocol and potentially provide more information for the
user on how to resolve the issue.
At least D-Link DIR-600 and DIR-825 have been reported to include
an extra octet after the Network Key attribute within a Credential
attribute. This can happen at least when they are provisioning an
open network.
Add a workaround to detect this incorrectly encoded attribute and
to skip the extra octet when parsing such a Credential.
We need to clear the selected registrar timeout from wps_er_learn
when stopping the protocol run at M7 (previously, this was done only
when WSC_Done was being processed). In addition, we need to cancel
the timeout when a new PBC operation is started.
Need to figure out whether the message is from a WSC 2.0 -based
device based on the unencrypted attributes, not the contents of the
encrypted data since the Version2 subelement is only included in the
unencrypted area.
Instead of build time options (CONFIG_WPS_TESTING_EXTRA_CRED and
CONFIG_WPS_EXTENSIBILITY_TESTING), use a single build option
(CONFIG_WPS_TESTING) and runtime configuration of which testing
operations are enabled. This allows a single binary to be used
for various tests.
The runtime configuration can be done through control interface
with wpa_cli/hostapd_cli commands:
Enable extensibility tests:
set wps_version_number 0x57
Disable extensibility tests (WPS2 build):
set wps_version_number 0x20
Enable extra credential tests:
set wps_testing_dummy_cred 1
Disable extra credential tests:
set wps_testing_dummy_cred 0
The Beacon frame must include UUID-E and RF Bands attributes when
in active PBC mode to allow stations to figure out that two BSSes in
PBC mode is not a PBC session overlap.
A new ctrl_interface command, WPS_CANCEL, can now be used to cancel
a pending or ongoing WPS operation. For now, this is only available
with wpa_supplicant (either in station or AP mode). Similar
functionality should be added for hostapd, too.
The WSC 2.0 specification moved to use another design for the new
attributes to avoid backwards compatibility issues with some
deployed implementations.
If CONFIG_WPS_STRICT is set, validate WPS IE(s) in management frames and
reject the frames if any of the mandatory attributes is missing or if an
included attribute uses an invalid value. In addition, verify that all
mandatory attributes are included and have valid values in the WSC
messages.
If all the device information attributes use their maximum lengths,
a single WPS IE is not enough to fit in all the data and as such,
we must be able to fragment the data. In addition, the wpabuf needs
to be allocated larger to fit in maximum data.
Instead of using 0x00 as the extra character, use space (' ') to
avoid failing tests that verify that the variable length string
attributes are not null terminated. In addition, this workaround
can now be disabled by defining CONFIG_WPS_STRICT for the build.
This can be done by adding following line to .config:
CFLAGS += -DCONFIG_WPS_STRICT
However, it should be noted that such a build may not interoperate
with some deployed WPS 1.0 -based implementations and as such, is
mainly designed for testing.
Whenever wpa_supplication is using Request Type Enrollee, it is trying
to enroll into a network. Indicate this with the explicit inclusion of
Request to Enroll attribute with value TRUE.
Advertize list of authorized enrollee MAC addresses in Beacon and
Probe Response frames and use these when selecting the AP. In order
to provide the list, the enrollee MAC address should be specified
whenever adding a new PIN. In addition, add UUID-R into
SetSelectedRegistrar action to make it potentially easier for an AP
to figure out which ER sent the action should there be multiple ERs
using the same IP address.
This adds definitions and parsing of the new attributes that were added
in WPS 2.0. In addition, the version negotiation is updated to use the
new mechanism, i.e., accept everything received and use the new Version2
attribute in transmitted messages.
There is no need to process the public key and generate keys if
the AP is going to reject this M2 anyway. This limits effect of
potential CPU DoS attacks in cases where AP PIN is disabled.
A new hostapd_cli command, wps_ap_pin, can now be used to manage
AP PIN at runtime. This can be used to generate a random AP PIN and
to only enable the AP PIN for short period (e.g., based on user
action on the AP device). Use of random AP PIN that is only enabled
for short duration is highly recommended to avoid security issues
with a static AP PIN.
This can happen on the AP if the AP PIN is not configured and
the client tries to go through the protocol instead of just using
Registrar mode to receive M1 from the AP. It is cleaner to send
out the WSC_NACK instead of just stopping the protocol.
In theory, this should not really be needed, but Windows 7 uses
Registrar mode to probe AP's WPS capabilities before trying to use
Enrollee and fails if the AP does not allow that probing to happen.
This allows the AP to start as an Enrollee and send M1, but refuse
to continue beyond that (M3 will not be sent if AP PIN is not known).
It looks like 10.6.3 and 10.6.4 do not like to receive Network Key
with WPA passphrase while PSK format still works. Use peer information
from M1 to figure out whether the Enrollee is likely to be OS X and
if so, force PSK format to be used for Network Key.
The AP configuration may change after provisioning, so it is better
not to use the current security policy to prioritize results. Instead,
use WPS Selected Registrar attribute as the main sorting key and use
signal strength next without considering security policy or rate sets.
The non-WPS provisioning case remains as-is, i.e., this change applies
only when trying to find an AP for WPS provisioning.
Some deployed implementations do not include the mandatory Network
Key attribute when a WPS Credential is for an open network. Allow
this to improve interoperability since the actual key value is not
really needed for open networks.
wps_er_config can now be used to configure an AP. It is similar to
wps_er_learn, but instead of only learning the current AP settings,
it continues to send M8 with the new settings for the AP.
wps_er_start command now takes an optional parameter that can be used
to configure a filter to only allow UPnP SSDP messages from the
specified IP address. In practice, this limits the WPS ER operations
to a single AP and filters out all other devices in the network.
When starting the protocol run with an Enrollee, clone the AP Settings
and replace the AP MAC Address with the Enrollee MAC Address so that the
correct value is then used in the Credential attribute in M8.
If the associating station indicates that it is intents to use WPS
by including WPS IE in (Re)Association Request frame, include WPS IE
in (Re)Association Response frame.
