Crypto library wrappers can now override the internal DH (group 5)
implementation. As a starting point, this is done with OpenSSL. The
new mechanism is currently available only for WPS (i.e., IKEv2 still
depends on the internal DH implementation).
The new file wps_nfc.c and ndef.c implements NFC device independent
operation, wps_nfc_pn531.c implements NFC device dependent operation.
This patch is only for the following use case:
- Enrollee = wpa_supplicant
- Registrar = hostapd internal Registrar
Following NFC methods can be used:
- Enrollee PIN with NFC
- Registrar PIN with NFC
- unencrypted credential with NFC
Encrypted credentials are not supported.
Enrollee side operation:
Registrar side operation:
Example configuration.
CONFIG_WPS=y
CONFIG_WPS_NFC=y
CONFIG_WPS_NFC_PN531=y
I used NFC device "NXP PN531". The NFC device access method is
confidential, so I used outer library. Please download below files from
https://www.saice-wpsnfc.bz/index.php
[WPS NFC Library]
WpsNfcLibrary/WpsNfc.h
WpsNfcLibrary/WpsNfcType.h
WpsNfcLibrary/WpsNfcVersion.h
WpsNfcLibrary/linux/libnfc_mapping_pn53x.dll
WpsNfcLibrary/linux/wpsnfc.dll
[NFC Reader/Writer Kernel Driver]
NFCKernelDriver-1.0.3/linux/kobj/sonyrw.ko
<WiFi test>
The hostapd/wpa_supplicant with this patch passed below tests on
"Wi-Fi WPS Test Plan Version 1.6".
4.2.5 Add device using NFC Method with password token
(I used SONY STA instead of NXP STA.)
4.2.6 Add device using NFC Method with configuration token
5.1.9 Add to AP using NFC Method with password token
through internal registrar
(I used SONY AP instead of NXP AP.)
5.1.10 Add to AP using NFC Method with configuration token
through internal registrar
Not all embedded devices have USB interface and it is useful to be able
to remove unneeded functionality from the binary. In addition, the
current implementation has some UNIX specific calls in it which may make
it not compile cleanly on all target systems.
If a Registrar tries to configure the AP, but fails to validate the
device password (AP PIN), lock the AP setup after four failures. This
protects the AP PIN against brute force guessing attacks.
WPS spec is not very specific on the presentation used for the DH
values. The Public Key attribute is described to be 192 octets long, so
that could be interpreted to imply that other places use fixed length
presentation for the DH keys. Change the DH derivation to use fixed
length bufferd by zero padding them from beginning if needed. This can
resolve infrequent (about 1/256 chance for both Public Key and Shared
Key being shorter) interop issues.
This callback is now used to stop wpa_supplicant from trying to continue
using parameters (most likely, device password) that do not work in a
loop. In addition, wpa_gui can now notify user of failed registration.
These functions fit in better with the category of functions included in
wps.c. wps_common.c is now used for generic helper functions (currently,
only crypto code).
WPS IE is now passed from hostapd association processing into EAP-WSC
and WPS processing. Request Type attribute is parsed from this
information and if the request is for a WLAN Manager Registrar,
additional management keys are derived (to be used with UPnP).
The core processing of attributes into struct wps_credential is now in
wps_common.c (was in wps_enrollee.c), so that the same code can be
shared with Registrar.
This adds WPS support for both hostapd and wpa_supplicant. Both programs
can be configured to act as WPS Enrollee and Registrar. Both PBC and PIN
methods are supported.
Currently, hostapd has more complete configuration option for WPS
parameters and wpa_supplicant configuration style will likely change in
the future. External Registrars are not yet supported in hostapd or
wpa_supplicant. While wpa_supplicant has initial support for acting as
an Registrar to configure an AP, this is still using number of hardcoded
parameters which will need to be made configurable for proper operation.