Commit Graph

313 Commits

Author SHA1 Message Date
Stefan Lippers-Hollmann
8f17c019a1 hostapd: fix CVE-2019-9497, CVE-2019-9498, CVE-2019-9499
EAP-pwd missing commit validation

Published: April 10, 2019
Identifiers:
- CVE-2019-9497 (EAP-pwd server not checking for reflection attack)
- CVE-2019-9498 (EAP-pwd server missing commit validation for
  scalar/element)
- CVE-2019-9499 (EAP-pwd peer missing commit validation for
  scalar/element)

Latest version available from: https://w1.fi/security/2019-4/

Vulnerability

EAP-pwd implementation in hostapd (EAP server) and wpa_supplicant (EAP
peer) was discovered not to validate the received scalar and element
values in EAP-pwd-Commit messages properly. This could result in attacks
that would be able to complete EAP-pwd authentication exchange without
the attacker having to know the used password.

A reflection attack is possible against the EAP-pwd server since the
hostapd EAP server did not verify that the EAP-pwd-Commit contains
scalar/element values that differ from the ones the server sent out
itself. This allows the attacker to complete EAP-pwd authentication
without knowing the password, but this does not result in the attacker
being able to derive the session key (MSK), i.e., the attacker would not
be able to complete the following key exchange (e.g., 4-way handshake in
RSN/WPA).

An attack using invalid scalar/element values is possible against both
the EAP-pwd server and peer since hostapd and wpa_supplicant did not
validate these values in the received EAP-pwd-Commit messages. If the
used crypto library does not implement additional checks for the element
(EC point), this could result in attacks where the attacker could use a
specially crafted commit message values to manipulate the exchange to
result in deriving a session key value from a very small set of possible
values. This could further be used to attack the EAP-pwd server in a
practical manner. An attack against the EAP-pwd peer is slightly more
complex, but still consider practical. These invalid scalar/element
attacks could result in the attacker being able to complete
authentication and learn the session key and MSK to allow the key
exchange to be completed as well, i.e., the attacker gaining access to
the network in case of the attack against the EAP server or the attacker
being able to operate a rogue AP in case of the attack against the EAP
peer.

While similar attacks might be applicable against SAE, it should be
noted that the SAE implementation in hostapd and wpa_supplicant does
have the validation steps that were missing from the EAP-pwd
implementation and as such, these attacks do not apply to the current
SAE implementation. Old versions of wpa_supplicant/hostapd did not
include the reflection attack check in the SAE implementation, though,
since that was added in June 2015 for v2.5 (commit 6a58444d27fd 'SAE:
Verify that own/peer commit-scalar and COMMIT-ELEMENT are different').

Vulnerable versions/configurations

All hostapd versions with EAP-pwd support (CONFIG_EAP_PWD=y in the build
configuration and EAP-pwd being enabled in the runtime configuration)
are vulnerable against the reflection attack.

All wpa_supplicant and hostapd versions with EAP-pwd support
(CONFIG_EAP_PWD=y in the build configuration and EAP-pwd being enabled
in the runtime configuration) are vulnerable against the invalid
scalar/element attack when built against a crypto library that does not
have an explicit validation step on imported EC points. The following
list indicates which cases are vulnerable/not vulnerable:
- OpenSSL v1.0.2 or older: vulnerable
- OpenSSL v1.1.0 or newer: not vulnerable
- BoringSSL with commit 38feb990a183 ('Require that EC points are on the
  curve.') from September 2015: not vulnerable
- BoringSSL without commit 38feb990a183: vulnerable
- LibreSSL: vulnerable
- wolfssl: vulnerable

Acknowledgments

Thanks to Mathy Vanhoef (New York University Abu Dhabi) for discovering
and reporting the issues and for proposing changes to address them in
the implementation.

Possible mitigation steps

- Merge the following commits to wpa_supplicant/hostapd and rebuild:

  CVE-2019-9497:
  EAP-pwd server: Detect reflection attacks

  CVE-2019-9498:
  EAP-pwd server: Verify received scalar and element
  EAP-pwd: Check element x,y coordinates explicitly

  CVE-2019-9499:
  EAP-pwd client: Verify received scalar and element
  EAP-pwd: Check element x,y coordinates explicitly

  These patches are available from https://w1.fi/security/2019-4/

- Update to wpa_supplicant/hostapd v2.8 or newer, once available

Signed-off-by: Stefan Lippers-Hollmann <s.l-h@gmx.de>
[bump PKG_RELEASE]
Signed-off-by: Jo-Philipp Wich <jo@mein.io>
2019-04-11 11:26:01 +02:00
Stefan Lippers-Hollmann
57ab9e3add hostapd: fix CVE-2019-9496
hostapd: fix SAE confirm missing state validation

Published: April 10, 2019
Identifiers:
- CVE-2019-9496 (SAE confirm missing state validation in hostapd/AP)
Latest version available from: https://w1.fi/security/2019-3/

Vulnerability

When hostapd is used to operate an access point with SAE (Simultaneous
Authentication of Equals; also known as WPA3-Personal), an invalid
authentication sequence could result in the hostapd process terminating
due to a NULL pointer dereference when processing SAE confirm
message. This was caused by missing state validation steps when
processing the SAE confirm message in hostapd/AP mode.

Similar cases against the wpa_supplicant SAE station implementation had
already been tested by the hwsim test cases, but those sequences did not
trigger this specific code path in AP mode which is why the issue was
not discovered earlier.

An attacker in radio range of an access point using hostapd in SAE
configuration could use this issue to perform a denial of service attack
by forcing the hostapd process to terminate.

Vulnerable versions/configurations

All hostapd versions with SAE support (CONFIG_SAE=y in the build
configuration and SAE being enabled in the runtime configuration).

Possible mitigation steps

- Merge the following commit to hostapd and rebuild:

  SAE: Fix confirm message validation in error cases

  These patches are available from https://w1.fi/security/2019-3/

- Update to hostapd v2.8 or newer, once available

Signed-off-by: Stefan Lippers-Hollmann <s.l-h@gmx.de>
[bump PKG_RELEASE]
Signed-off-by: Jo-Philipp Wich <jo@mein.io>
2019-04-11 11:26:01 +02:00
Stefan Lippers-Hollmann
262229e924 hostapd: fix CVE-2019-9495
EAP-pwd side-channel attack

Published: April 10, 2019
Identifiers:
- CVE-2019-9495 (cache attack against EAP-pwd)
Latest version available from: https://w1.fi/security/2019-2/

Vulnerability

Number of potential side channel attacks were recently discovered in the
SAE implementations used by both hostapd and wpa_supplicant (see
security advisory 2019-1 and VU#871675). EAP-pwd uses a similar design
for deriving PWE from the password and while a specific attack against
EAP-pwd is not yet known to be tested, there is no reason to believe
that the EAP-pwd implementation would be immune against the type of
cache attack that was identified for the SAE implementation. Since the
EAP-pwd implementation in hostapd (EAP server) and wpa_supplicant (EAP
peer) does not support MODP groups, the timing attack described against
SAE is not applicable for the EAP-pwd implementation.

A novel cache-based attack against SAE handshake would likely be
applicable against the EAP-pwd implementation. Even though the
wpa_supplicant/hostapd PWE derivation iteration for EAP-pwd has
protections against timing attacks, this new cache-based attack might
enable an attacker to determine which code branch is taken in the
iteration if the attacker is able to run unprivileged code on the victim
machine (e.g., an app installed on a smart phone or potentially a
JavaScript code on a web site loaded by a web browser). This depends on
the used CPU not providing sufficient protection to prevent unprivileged
applications from observing memory access patterns through the shared
cache (which is the most likely case with today's designs).

The attacker could use information about the selected branch to learn
information about the password and combine this information from number
of handshake instances with an offline dictionary attack. With
sufficient number of handshakes and sufficiently weak password, this
might result in full recovery of the used password if that password is
not strong enough to protect against dictionary attacks.

This attack requires the attacker to be able to run a program on the
target device. This is not commonly the case on an authentication server
(EAP server), so the most likely target for this would be a client
device using EAP-pwd.

The commits listed in the end of this advisory change the EAP-pwd
implementation shared by hostapd and wpa_supplicant to perform the PWE
derivation loop using operations that use constant time and memory
access pattern to minimize the externally observable differences from
operations that depend on the password even for the case where the
attacker might be able to run unprivileged code on the same device.

Vulnerable versions/configurations

All wpa_supplicant and hostapd versions with EAP-pwd support
(CONFIG_EAP_PWD=y in the build configuration and EAP-pwd being enabled
in the runtime configuration).

It should also be noted that older versions of wpa_supplicant/hostapd
prior to v2.7 did not include additional protection against certain
timing differences. The definition of the EAP-pwd (RFC 5931) does not
describe such protection, but the same issue that was addressed in SAE
earlier can be applicable against EAP-pwd as well and as such, that
implementation specific extra protection (commit 22ac3dfebf7b, "EAP-pwd:
Mask timing of PWE derivation") is needed to avoid showing externally
visible timing differences that could leak information about the
password. Any uses of older wpa_supplicant/hostapd versions with EAP-pwd
are recommended to update to v2.7 or newer in addition to the mitigation
steps listed below for the more recently discovered issue.

Possible mitigation steps

- Merge the following commits to wpa_supplicant/hostapd and rebuild:

  OpenSSL: Use constant time operations for private bignums
  Add helper functions for constant time operations
  OpenSSL: Use constant time selection for crypto_bignum_legendre()
  EAP-pwd: Use constant time and memory access for finding the PWE

  These patches are available from https://w1.fi/security/2019-2/

- Update to wpa_supplicant/hostapd v2.8 or newer, once available

- Use strong passwords to prevent dictionary attacks

Signed-off-by: Stefan Lippers-Hollmann <s.l-h@gmx.de>
[bump PKG_RELEASE]
Signed-off-by: Jo-Philipp Wich <jo@mein.io>
2019-04-11 11:26:01 +02:00
Stefan Lippers-Hollmann
af606d077f hostapd: fix CVE-2019-9494
SAE side-channel attacks

Published: April 10, 2019
Identifiers:
- VU#871675
- CVE-2019-9494 (cache attack against SAE)
Latest version available from: https://w1.fi/security/2019-1/

Vulnerability

Number of potential side channel attacks were discovered in the SAE
implementations used by both hostapd (AP) and wpa_supplicant
(infrastructure BSS station/mesh station). SAE (Simultaneous
Authentication of Equals) is also known as WPA3-Personal. The discovered
side channel attacks may be able to leak information about the used
password based on observable timing differences and cache access
patterns. This might result in full password recovery when combined with
an offline dictionary attack and if the password is not strong enough to
protect against dictionary attacks.

Cache attack

A novel cache-based attack against SAE handshake was discovered. This
attack targets SAE with ECC groups. ECC group 19 being the mandatory
group to support and the most likely used group for SAE today, so this
attack applies to the most common SAE use case. Even though the PWE
derivation iteration in SAE has protections against timing attacks, this
new cache-based attack enables an attacker to determine which code
branch is taken in the iteration if the attacker is able to run
unprivileged code on the victim machine (e.g., an app installed on a
smart phone or potentially a JavaScript code on a web site loaded by a
web browser). This depends on the used CPU not providing sufficient
protection to prevent unprivileged applications from observing memory
access patterns through the shared cache (which is the most likely case
with today's designs).

The attacker can use information about the selected branch to learn
information about the password and combine this information from number
of handshake instances with an offline dictionary attack. With
sufficient number of handshakes and sufficiently weak password, this
might result in full discovery of the used password.

This attack requires the attacker to be able to run a program on the
target device. This is not commonly the case on access points, so the
most likely target for this would be a client device using SAE in an
infrastructure BSS or mesh BSS.

The commits listed in the end of this advisory change the SAE
implementation shared by hostapd and wpa_supplicant to perform the PWE
derivation loop using operations that use constant time and memory
access pattern to minimize the externally observable differences from
operations that depend on the password even for the case where the
attacker might be able to run unprivileged code on the same device.

Timing attack

The timing attack applies to the MODP groups 22, 23, and 24 where the
PWE generation algorithm defined for SAE can have sufficient timing
differences for an attacker to be able to determine how many rounds were
needed to find the PWE based on the used password and MAC
addresses. When the attack is repeated with multiple times, the attacker
may be able to gather enough information about the password to be able
to recover it fully using an offline dictionary attack if the password
is not strong enough to protect against dictionary attacks. This attack
could be performed by an attacker in radio range of an access point or a
station enabling the specific MODP groups.

This timing attack requires the applicable MODP groups to be enabled
explicitly in hostapd/wpa_supplicant configuration (sae_groups
parameter). All versions of hostapd/wpa_supplicant have disabled these
groups by default.

While this security advisory lists couple of commits introducing
additional protection for MODP groups in SAE, it should be noted that
the groups 22, 23, and 24 are not considered strong enough to meet the
current expectation for a secure system. As such, their use is
discouraged even if the additional protection mechanisms in the
implementation are included.

Vulnerable versions/configurations

All wpa_supplicant and hostapd versions with SAE support (CONFIG_SAE=y
in the build configuration and SAE being enabled in the runtime
configuration).

Acknowledgments

Thanks to Mathy Vanhoef (New York University Abu Dhabi) and Eyal Ronen
(Tel Aviv University) for discovering the issues and for discussions on
how to address them.

Possible mitigation steps

- Merge the following commits to wpa_supplicant/hostapd and rebuild:

  OpenSSL: Use constant time operations for private bignums
  Add helper functions for constant time operations
  OpenSSL: Use constant time selection for crypto_bignum_legendre()
  SAE: Minimize timing differences in PWE derivation
  SAE: Avoid branches in is_quadratic_residue_blind()
  SAE: Mask timing of MODP groups 22, 23, 24
  SAE: Use const_time selection for PWE in FFC
  SAE: Use constant time operations in sae_test_pwd_seed_ffc()

  These patches are available from https://w1.fi/security/2019-1/

- Update to wpa_supplicant/hostapd v2.8 or newer, once available

- In addition to either of the above alternatives, disable MODP groups
  1, 2, 5, 22, 23, and 24 by removing them from hostapd/wpa_supplicant
  sae_groups runtime configuration parameter, if they were explicitly
  enabled since those groups are not considered strong enough to meet
  current security expectations. The groups 22, 23, and 24 are related
  to the discovered side channel (timing) attack. The other groups in
  the list are consider too weak to provide sufficient security. Note
  that all these groups have been disabled by default in all
  hostapd/wpa_supplicant versions and these would be used only if
  explicitly enabled in the configuration.

- Use strong passwords to prevent dictionary attacks

Signed-off-by: Stefan Lippers-Hollmann <s.l-h@gmx.de>
[bump PKG_RELEASE]
Signed-off-by: Jo-Philipp Wich <jo@mein.io>
2019-04-11 11:26:01 +02:00
Arnout Vandecappelle (Essensium/Mind)
2e0f41e73a hostapd: add Multi-AP patches and config options
Cherry-pick Multi-AP commits from uptream:
 9c06f0f6a hostapd: Add Multi-AP protocol support
 5abc7823b wpa_supplicant: Add Multi-AP backhaul STA support
 a1debd338 tests: Refactor test_multi_ap
 bfcdac1c8 Multi-AP: Don't reject backhaul STA on fronthaul BSS
 cb3c156e7 tests: Update multi_ap_fronthaul_on_ap to match implementation
 56a2d788f WPS: Add multi_ap_subelem to wps_build_wfa_ext()
 83ebf5586 wpa_supplicant: Support Multi-AP backhaul STA onboarding with WPS
 66819b07b hostapd: Support Multi-AP backhaul STA onboarding with WPS
 8682f384c hostapd: Add README-MULTI-AP
 b1daf498a tests: Multi-AP WPS provisioning

Add support for Multi-AP to the UCI configuration. Every wifi-iface gets
an option 'multi_ap'. For APs, its value can be 0 (multi-AP support
disabled), 1 (backhaul AP), 2 (fronthaul AP), or 3 (fronthaul + backhaul
AP). For STAs, it can be 0 (not a backhaul STA) or 1 (backhaul STA, can
only associate with backhaul AP).

Also add new optional parameter to wps_start ubus call of
wpa_supplicant to indicate that a Multi-AP backhaul link is required.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
2019-02-20 13:17:11 +01:00
Felix Fietkau
5b6997dcb3 hostapd: update the fix for a race condition in mesh new peer handling
Prevent the mesh authentication state machine from getting reset on bogus
new peer discovery

Signed-off-by: Felix Fietkau <nbd@nbd.name>
2019-02-17 16:06:44 +01:00
Felix Fietkau
f948aa4d4f hostapd: enable CONFIG_DEBUG_SYSLOG for wpa_supplicant
It was already enabled for wpad builds and since commit 6a15077e2d
the script relies on it. Size impact is minimal (2 kb on MIPS .ipk).

Signed-off-by: Felix Fietkau <nbd@nbd.name>
2019-02-17 13:05:14 +01:00
Felix Fietkau
db93949aa3 hostapd: fix race condition in mesh new peer handling
Avoid trying to add the same station to the driver multiple times

Signed-off-by: Felix Fietkau <nbd@nbd.name>
2019-02-12 15:12:35 +01:00
Felix Fietkau
6a15077e2d hostapd: send wpa_supplicant logging output to syslog
Helpful for debugging network connectivity issues

Signed-off-by: Felix Fietkau <nbd@nbd.name>
2019-02-12 15:12:35 +01:00
Felix Fietkau
4443804b54 wpa_supplicant: fix calling channel switch via wpa_cli on mesh interfaces
Signed-off-by: Felix Fietkau <nbd@nbd.name>
2019-01-29 11:27:13 +01:00
Felix Fietkau
ae6b5815cd hostapd: add support for passing CSA events from sta/mesh to AP interfaces
Fixes handling CSA when using AP+STA or AP+Mesh

Signed-off-by: Felix Fietkau <nbd@nbd.name>
2019-01-29 11:27:06 +01:00
Hauke Mehrtens
99956528df hostapd: update to version 2018-12-02 (2.7)
This updates hostapd to version the git version from 2018-12-02 which
matches the 2.7 release.

The removed patches were are already available in the upstream code, one
additional backport is needed to fix a compile problem.

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
2019-01-02 15:47:13 +01:00
Hauke Mehrtens
835947ce64 hostapd: Make eapol-test depend on libubus
The eapol-test application also uses the code with the newly activated
ubus support, add the missing dependency.

Fixes: f5753aae23 ("hostapd: add support for WPS pushbutton station")
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
2018-12-16 14:25:41 +01:00
Daniel Golle
f5753aae23 hostapd: add support for WPS pushbutton station
similar to hostapd, also add a ubus interface for wpa_supplicant
which will allow handling WPS push-button just as it works for hostapd.
In order to have wpa_supplicant running without any network
configuration (so you can use it to retrieve credentials via WPS),
configure wifi-iface in /etc/config/wireless:

  config wifi-iface 'default_radio0'
      option device 'radio0'
      option network 'wwan'
      option mode 'sta'
      option encryption 'wps'

This section will automatically be edited if credentials have
successfully been acquired via WPS.

Size difference (mips_24kc): roughly +4kb for the 'full' variants of
wpa_supplicant and wpad which do support WPS.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>
2018-12-12 09:37:23 +01:00
Kevin Darbyshire-Bryant
3a6bddd7f7 hostapd: add utf8_ssid flag & enable as default
SSIDs may contain UTF8 characters but ideally hostapd should be told
this is the case so it can advertise the fact. Default enable this
option.

add uci option utf8_ssid '0'/'1' for disable/enable e.g.

config wifi-iface
	option utf8_ssid '0'

Signed-off-by: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>
2018-11-14 17:41:18 +00:00
Kevin Darbyshire-Bryant
1063d904b7 hostapd: add basic variant
Add a basic variant which provides WPA-PSK only, 802.11r and 802.11w and
is intended to support 11r & 11w (subject to driver support) out of the
box.

Signed-off-by: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>
2018-10-16 15:07:41 +01:00
Jo-Philipp Wich
3e633bb370 hostapd: fix MAC filter related log spam
Backport two upstream fixes to address overly verbose logging of MAC ACL
rejection messages.

Fixes: FS#1468
Signed-off-by: Jo-Philipp Wich <jo@mein.io>
2018-10-16 12:11:20 +02:00
Hauke Mehrtens
4c3fae4adc hostapd: Add WPA-EAP-SUITE-B-192 (WPA3-Enterprise)
This adds support for the WPA3-Enterprise mode authentication.

The settings for the WPA3-Enterpriese mode are defined in
WPA3_Specification_v1.0.pdf. This mode also requires ieee80211w and
guarantees at least 192 bit of security.

This does not increase the ipkg size by a significant size.

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
2018-10-14 13:57:15 +02:00
Hauke Mehrtens
18c6c93a3b hostapd: Activate Opportunistic Wireless Encryption (OWE)
OWE is defined in RFC 8110 and provides encryption and forward security
for open networks.

This is based on the requirements in the Wifi alliance document
Opportunistic_Wireless_Encryption_Specification_v1.0_0.pdf
The wifi alliance requires ieee80211w for the OWE mode.
This also makes it possible to configure the OWE transission mode which
allows it operate an open and an OWE BSSID in parallel and the client
should only show one network.

This increases the ipkg size by 5.800 Bytes.
Old: 402.541 Bytes
New: 408.341 Bytes

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
2018-10-14 13:57:15 +02:00
Hauke Mehrtens
4a009a16d2 hostapd: Activate Simultaneous Authentication of Equals (SAE)
This build the full openssl and wolfssl versions with SAE support which
is the main part of WPA3 PSK.

This needs elliptic curve cryptography which is only provided by these
two external cryptographic libraries and not by the internal
implementation.

The WPA3_Specification_v1.0.pdf file says that in SAE only mode
Protected Management Frames (PMF) is required, in mixed mode with
WPA2-PSK PMF should be required for clients using SAE, and optional for
clients using WPA2-PSK. The defaults are set now accordingly.

This increases the ipkg size by 8.515 Bytes.
Old: 394.026 Bytes
New: 402.541 Bytes

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
2018-10-14 13:57:15 +02:00
Hauke Mehrtens
a1ad1144b6 hostapd: SAE: Do not ignore option sae_require_mfp
This patch was send for integration into the hostapd project.

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
2018-10-14 13:57:14 +02:00
Hauke Mehrtens
779773a0de hostapd: backport build fix when OWE is activated
This backports a compile fix form the hostapd project.

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
2018-10-14 13:57:14 +02:00
Hauke Mehrtens
4b93b03577 hostapd: sync config with default configuration
This replaces the configuration files with the versions from the hostapd
project and the adaptions done by OpenWrt.

The resulting binaries should be the same.

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
2018-10-14 13:57:14 +02:00
Enrique Giraldo
61454a0a8c hostapd: add acs feature indication
Signed-off-by: Enrique Giraldo <enrique.giraldo@galgus.net>
2018-09-29 17:23:11 +02:00
Rosen Penev
f78e07ad2a hostapd: Fix compile with OpenSSL 1.1.0 + no deprecated APIs
Patch was accepted upsteam:

https://w1.fi/cgit/hostap/commit/?id=373c796948599a509bad71695b5b72eef003f661

Signed-off-by: Rosen Penev <rosenp@gmail.com>
2018-09-10 09:01:37 +02:00
Alexander Couzens
967d6460c0
hostapd: fix build of wpa-supplicant-p2p
VARIANT:= got removed by accident.

Fixes: 3838b16943 ("hostapd: fix conflicts hell")
Signed-off-by: Alexander Couzens <lynxis@fe80.eu>
2018-09-03 21:51:06 +02:00
Yury Shvedov
cad9519eba hostapd: process all CSA parameters
This adds processing of all CSA arguments from ubus switch_chan request
in the same manner as in the control interface API.

Signed-off-by: Yury Shvedov <yshvedov@wimarksystems.com>
2018-08-20 09:24:43 +02:00
John Crispin
1961948585 wpa_supplicant: fix CVE-2018-14526
Unauthenticated EAPOL-Key decryption in wpa_supplicant

Published: August 8, 2018
Identifiers:
- CVE-2018-14526
Latest version available from: https://w1.fi/security/2018-1/

Vulnerability

A vulnerability was found in how wpa_supplicant processes EAPOL-Key
frames. It is possible for an attacker to modify the frame in a way that
makes wpa_supplicant decrypt the Key Data field without requiring a
valid MIC value in the frame, i.e., without the frame being
authenticated. This has a potential issue in the case where WPA2/RSN
style of EAPOL-Key construction is used with TKIP negotiated as the
pairwise cipher. It should be noted that WPA2 is not supposed to be used
with TKIP as the pairwise cipher. Instead, CCMP is expected to be used
and with that pairwise cipher, this vulnerability is not applicable in
practice.

When TKIP is negotiated as the pairwise cipher, the EAPOL-Key Key Data
field is encrypted using RC4. This vulnerability allows unauthenticated
EAPOL-Key frames to be processed and due to the RC4 design, this makes
it possible for an attacker to modify the plaintext version of the Key
Data field with bitwise XOR operations without knowing the contents.
This can be used to cause a denial of service attack by modifying
GTK/IGTK on the station (without the attacker learning any of the keys)
which would prevent the station from accepting received group-addressed
frames. Furthermore, this might be abused by making wpa_supplicant act
as a decryption oracle to try to recover some of the Key Data payload
(GTK/IGTK) to get knowledge of the group encryption keys.

Full recovery of the group encryption keys requires multiple attempts
(128 connection attempts per octet) and each attempt results in
disconnection due to a failure to complete the 4-way handshake. These
failures can result in the AP/network getting disabled temporarily or
even permanently (requiring user action to re-enable) which may make it
impractical to perform the attack to recover the keys before the AP has
already changes the group keys. By default, wpa_supplicant is enforcing
at minimum a ten second wait time between each failed connection
attempt, i.e., over 20 minutes waiting to recover each octet while
hostapd AP implementation uses 10 minute default for GTK rekeying when
using TKIP. With such timing behavior, practical attack would need large
number of impacted stations to be trying to connect to the same AP to be
able to recover sufficient information from the GTK to be able to
determine the key before it gets changed.

Vulnerable versions/configurations

All wpa_supplicant versions.

Acknowledgments

Thanks to Mathy Vanhoef of the imec-DistriNet research group of KU
Leuven for discovering and reporting this issue.

Possible mitigation steps

- Remove TKIP as an allowed pairwise cipher in RSN/WPA2 networks. This
can be done also on the AP side.

- Merge the following commits to wpa_supplicant and rebuild:

WPA: Ignore unauthenticated encrypted EAPOL-Key data

This patch is available from https://w1.fi/security/2018-1/

- Update to wpa_supplicant v2.7 or newer, once available

Signed-off-by: John Crispin <john@phrozen.org>
2018-08-10 15:48:21 +02:00
Nick Hainke
abefb4fda3 hostapd: add ht and vht support in handle event function Add ht and vht capabilities. If a device sends a probe request, the capabilities are added.
Signed-off-by: Nick Hainke <vincent@systemli.org>
2018-07-30 11:01:04 +02:00
Nick Hainke
74ac742277 hostapd: add ubus call for ap features
The call "get_features" allows to gather hostapd config options
via ubus. As first infos we add the ht and vht support.
Although nl80211 supports to gather informations about
ht and vht capabilities, the hostapd configuration can disable
vht and ht. However, it is possible that the iw output is not
representing the actual hostapd configuration.

Signed-off-by: Nick Hainke <vincent@systemli.org>
2018-07-30 10:59:25 +02:00
Felix Fietkau
f0ac9afe69 hostapd: remove unused struct hostapd_ubus_iface
Signed-off-by: Felix Fietkau <nbd@nbd.name>
2018-07-22 17:17:20 +02:00
Mathias Kresin
3838b16943 hostapd: fix conflicts hell
Add each variant to the matching PROVIDERS variables after evaluating
the respective hostapd*, wpad* and wpa* variant.

Each package providing the same feature will automatically conflict with
all prior packages providing the same feature.

This way we can handle the conflicts automatically without introducing
recursive dependencies.

Signed-off-by: Mathias Kresin <dev@kresin.me>
2018-07-18 19:17:46 +02:00
Mathias Kresin
8af8ceb1c8 hostapd: cleanup package definition
Move common variables and/or values to the package (variant) default.
Add additional values in variant packages if necessary. Remove further
duplicates by introducing new templates.

Remove the ANY_[HOSTAPD|SUPPLICANT_PROVIDERS]_PROVIDERS. The are the
same as the variables without the any prefix. No need to maintain both
variables.

Signed-off-by: Mathias Kresin <dev@kresin.me>
2018-07-18 19:17:46 +02:00
Felix Fietkau
6dac92a42e hostapd: build with LTO enabled (using jobserver for parallel build)
Signed-off-by: Felix Fietkau <nbd@nbd.name>
2018-07-10 14:26:35 +02:00
Denton Gentry
a84962ea35 hostapd: make cli treat UNKNOWN COMMAND as failing
Avoid infinite loop at 100% CPU when running hostapd_cli
if CONFIG_CTRL_IFACE_MIB is not defined.

  _newselect(4, [3], NULL, NULL, ...)
  recvfrom(3, "UNKNOWN COMMAND\n", 4095, 0, NULL, NULL) = 16
  sendto(3, "STA-NEXT UNKNOWN COMMAND", 24, 0, NULL, 0) = 24

Signed-off-by: Denton Gentry <denny@geekhold.com>
2018-06-07 09:27:50 +02:00
Daniel Golle
987900f2de hostapd: properly build hostapd-only SSL variants
Make sure hostapd-openssl is actually build against OpenSSL, same
for wolfSSL.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>
2018-06-05 15:33:35 +02:00
Felix Fietkau
7d8681ccb9 hostapd: expose device taxonomy signature via ubus
Signed-off-by: Felix Fietkau <nbd@nbd.name>
2018-06-05 09:28:04 +02:00
Felix Fietkau
23c1827e34 hostapd: add support for client taxonomy in the full config
This can be used to fingerprint clients to try to identify the exact
model

Signed-off-by: Felix Fietkau <nbd@nbd.name>
2018-06-05 09:28:00 +02:00
Daniel Golle
78f1974bc5 hostapd: update packaging and patches
Clean up conflicts/provides/depends hell and add PROVIDES for
eapol-test variants while at it.
Update mesh-DFS patchset from Peter Oh to v5 (with local fixes) which
allows to drop two revert-patches for upstream commits which previously
were necessary to un-break mesh-DFS support.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>
2018-05-31 00:38:16 +02:00
Daniel Golle
c8fdd0e9c8 hostapd: convert ssl provider build options to variants
Instead of selecting the SSL provider at compile time, build package
variants for each option so users can select the binary package without
having to build it themselves.
Most likely not all variants have actually ever been user by anyone.
We should reduce the selection to the reasonable and most used
combinations at some point in future. For now, build them all.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>
2018-05-25 16:01:59 +02:00
Daniel Golle
69f544937f hostapd: update to git HEAD of 2018-05-21, allow build against wolfssl
Support for building wpa_supplicant/hostapd against wolfssl has been
added upstream recently, add build option to allow users using it.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>
2018-05-24 22:21:10 +02:00
Gospod Nassa
3cc56a5534 hostapd: fix IEEE 802.11r (fast roaming) defaults
Use ft_psk_generate_local=1 by default, as it makes everything else fairly
trivial. All of the r0kh/r1kh and key management stuff goes away and hostapd
fairly much does it all	for us.

We do need to provide nas_identifier, which can	be derived from	the BSSID,
and we need to generate	a mobility_domain, for which we	default	to the first
four chars of the md5sum of the	SSID.

The complex manual setup should also still work, but the defaults also
now work easily out of the box. Verified by manually running hostapd
(with the autogenerated config) and watching the debug output:

wlan2: STA ac:37:43:a0:a6:ae WPA: FT authentication already completed - do not start 4-way handshake

 This was previous submitted to LEDE in
 https://github.com/lede-project/source/pull/1382

[dwmw2: Rewrote commit message]
Signed-off-by: Gospod Nassa <devianca@gmail.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2018-05-18 11:19:00 +02:00
Sven Eckelmann
ba5ec6b77c hostapd: fix VHT80 for encrypted mesh channel settings
The max_oper_chwidth settings was parsed incorrectly for big endian system.
This prevented the system to switch to VHT80 (or VHT160). Instead they were
mapped to:

* HT20:   20MHz
* VHT20:  20MHz
* HT40:   40MHz
* VHT40:  40MHz
* VHT80:  40MHz
* VHT160: 40MHz

This happened because each max_oper_chwidth setting in the config file was
parsed as "0" instead of the actual value.

Fixes: a4322eba2b ("hostapd: fix encrypted mesh channel settings")
Signed-off-by: Sven Eckelmann <sven.eckelmann@openmesh.com>
2018-05-14 19:07:37 +02:00
Daniel Golle
6e0fa4a76d hostapd: fix mesh+AP
Fix encrypted (or DFS) AP+MESH interface combination in a way similar
to how it's done for AP+STA and fix netifd shell script.
Refresh patches while at it.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>
2018-05-14 09:48:58 +02:00
Nick Hainke
0a7657c300 hostapd: add channel utilization as config option
Add the channel utilization as hostapd configuration option.

Signed-off-by: Nick Hainke <vincent@systemli.org>
2018-05-07 10:44:09 +02:00
Felix Fietkau
3a456683e5 hostapd: fix a mesh mode crash with CONFIG_TAXONOMY enabled
Signed-off-by: Felix Fietkau <nbd@nbd.name>
2018-05-03 12:38:33 +02:00
Daniel Golle
a4322eba2b hostapd: fix encrypted mesh channel settings
Import two patches from Peter Oh to allow setting channel
bandwidth in the way it already works for managed interfaces.
This fixes mesh interfaces on 802.11ac devices always coming up in
VHT80 mode.

Add a patch to allow HT40 also on 2.4GHz if noscan option is set, which
also skips secondary channel scan just like noscan works in AP mode.

This time also make sure to add all files to the patch before
committing it...

Signed-off-by: Daniel Golle <daniel@makrotopia.org>
2018-04-20 16:00:01 +02:00
Felix Fietkau
1a89547957 Revert "hostapd: fix encrypted mesh channel settings"
This reverts commit 7f52919a2f, which is
currently breaking the builds and needs to be reworked

Signed-off-by: Felix Fietkau <nbd@nbd.name>
2018-04-20 10:36:42 +02:00
Daniel Golle
7f52919a2f hostapd: fix encrypted mesh channel settings
Import two patches from Peter Oh to allow setting channel
bandwidth in the way it already works for managed interfaces.
This fixes mesh interfaces on 802.11ac devices always coming up in
VHT80 mode.

Add a patch to allow HT40 also on 2.4GHz if noscan option is set, which
also skips secondary channel scan just like noscan works in AP mode.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>
2018-04-20 07:52:19 +02:00
Daniel Golle
ff8df2b3f9 hostapd: mesh: make forwarding configurable
For unencrypted mesh networks our scripts take care of setting
the various mesh_param values. wpa_supplicant changes somes of them
when being used for SAE encrypted mesh and previously didn't allow
configuring any of them. Add support for setting mesh_fwding (which
has to be set to 0 when using other routing protocols on top of
802.11s) and update our script to pass the value to wpa_supplicant.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>
2018-04-18 22:12:18 +02:00