This adds mostly feature complete external Registrar support with the
main missing part being proper support for multiple external Registrars
working at the same time and processing of concurrent registrations when
using an external Registrar.
This code is based on Sony/Saice implementation
(https://www.saice-wpsnfc.bz/) and the changes made by Ted Merrill
(Atheros) to make it more suitable for hostapd design and embedded
systems. Some of the UPnP code is based on Intel's libupnp. Copyrights
and licensing are explained in src/wps/wps_upnp.c in more detail.
It looks like this never survived the move from IEEE 802.1X-2001 to
IEEE 802.1X-2004 and EAP state machine (RFC 4137). The retransmission
scheduling and control is now in EAP authenticator and the
calculateTimeout() producedure is used to determine timeout for
retransmission (either dynamic backoff or value from EAP method hint).
The recommended calculations based on SRTT and RTTVAR (RFC 2988) are not
yet implemented since there is no round-trip time measurement available
yet.
This should make EAP authentication much more robust in environments
where initial packets are lost for any reason. If the EAP method does
not provide a hint on timeout, default schedule of 3, 6, 12, 20, 20, 20,
... seconds will be used.
Previously, only the delivery option 1 from RFC 4284
(EAP-Request/Identity from the AP) was supported. Now option 3
(subsequent EAP-Request/Identity from RADIUS server) can also be used
when hostapd is used as a RADIUS server. The eap_user file will need to
have a Phase 1 user entry pointing to Identity method in order for this
to happen (e.g., "* Identity" in the end of the file). The identity hint
is configured in the same was as for AP/Authenticator case (eap_message
in hostapd.conf).
Changed peer to derive the full key (both MS-MPPE-Recv-Key and
MS-MPPE-Send-Key for total of 32 octets) to match with server
implementation.
Swapped the order of MPPE keys in MSK derivation since server
MS-MPPE-Recv-Key | MS-MPPE-Send-Key matches with the order specified for
EAP-TLS MSK derivation. This means that PEAPv0 cryptobinding is now
using EAP-MSCHAPv2 MSK as-is for ISK while EAP-FAST will need to swap
the order of the MPPE keys to get ISK in a way that interoperates with
Cisco EAP-FAST implementation.
Since only one KDF is currently supported, the negotiation is not
allowed and peer must be rejected if it tries to send KDF selection in a
Challenge message. The negotiation code is left in the file and just
commented out since it was tested to work and can be used in the future
if another KDF is added.
This allows the same source code file to be shared for both methods. For
now, this is only in eap_aka_prime.c, but eventually, changes in
eap_aka_prime.c are likely to be merged into eap_aka.c at which point
the separate eap_aka_prime.c can be removed.
This is just making an as-is copy of EAP-AKA server and peer
implementation into a new file and by using the different EAP method
type that is allocated for EAP-AKA' (50). None of the other differences
between EAP-AKA and EAP-AKA' are not yet included.
It is likely that once EAP-AKA' implementation is done and is found to
work correctly, large part of the EAP-AKA and EAP-AKA' code will be
shared. However, it is not reasonable to destabilize EAP-AKA
implementation at this point before it is clearer what the final
differences will be.
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).
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.
It the message was large enough to require fragmentation (e.g., if a large
Session Ticket data is included), More Fragment flag was set, but no
more fragments were actually sent (i.e., Access-Accept was sent out).
This change breaks interoperability with older wpa_supplicant versions
(everything up to and including wpa_supplicant 0.5.10 and 0.6.5) which
incorrectly used this field as number of bytes, not bits, in RES.
Instead of falling back to full TLS handshake on expired PAC, allow the
PAC to be used to allow a PAC update with some level of server
authentication (i.e., do not fall back to full TLS handshake since we
cannot be sure that the peer would be able to validate server certificate
now). However, reject the authentication since the PAC was not valid
anymore. Peer can connect again with the newly provisioned PAC after this.
Changed EAP-FAST configuration to use separate fields for A-ID and
A-ID-Info (eap_fast_a_id_info) to allow A-ID to be set to a fixed
16-octet len binary value for better interoperability with some peer
implementations; eap_fast_a_id is now configured as a hex string.
eap_fast_prov config parameter can now be used to enable/disable different
EAP-FAST provisioning modes:
0 = provisioning disabled
1 = only anonymous provisioning allowed
2 = only authenticated provisioning allowed
3 = both provisioning modes allowed
draft-cam-winget-eap-fast-provisioning-06.txt or RFC 4851 do not seem to
mandate any particular order for TLVs, but some interop issues were noticed
with an EAP-FAST peer implementation when Result TLV followed PAC TLV. The
example in draft-cam-winget-eap-fast-provisioning-06.txt shows the TLVs in
the other order, so change the order here, too, to make it less likely to
hit this type of interop issues.
It is possible that the initialization of the Phase 2 EAP method fails and
if that happens, we need to stop EAP-TTLS server from trying to continue
using the uninitialized EAP method. Otherwise, the server could trigger
a segmentation fault when dereferencing a NULL pointer.
The change to support fragmentation added extra function to generate the
EAP header, but forgot to remove the original code and ended up getting two
EAP headers and TNC flags field in the generated message. These header
fields need to be added only in the function that builds the final message
(and if necessary, fragments the data).
The server handshake processing was still using SSL_read() to get OpenSSL
to perform the handshake. While this works for most cases, it caused some
issues for re-authentication. This is now changed to use SSL_accept() which
is more approriate here since we know that the handshake is still going on
and there will not be any tunneled data available. This resolves some of
the re-authentication issues and makes it possible for the server to notice
if TLS processing fails (SSL_read() did not return an error in many of
these cases while SSL_accept() does).
Set session id context to a unique value in order to avoid fatal errors
when client tries session resumption (SSL_set_session_id_context() must be
called for that to work), but disable session resumption with the unique
value for the time being since not all server side code is ready for it yet
(e.g., EAP-TTLS needs special Phase 2 processing when using abbreviated
handshake).
Changed EAP-TLS server not to call TLS library when processing the final
ACK (empty data) from the client in order to avoid starting a new TLS
handshake with SSL_accept().
Move the basic processing of received frames into eap_tls_common.c and use
callback functions to handle EAP type specific processing of the version
field and payload.
Fragmentation is now done as a separate step to clean up the design and to
allow the same code to be used in both Phase 1 and Phase 2. This adds
support for fragmenting EAP-PEAP/TTLS/FAST Phase 2 (tunneled) data.
Need to clear the state back to MSG after having processed all incoming
fragments. Without this, the server got stuck in sending the fragment ACK
even after having received the full message.
Even though we try to disable TLS compression, it is possible that this
cannot be done with all TLS libraries. For example, OpenSSL 0.9.8 does not
seem to have a configuration item for disabling all compression (0.9.9 has
such an option). If compression is used, Phase 2 decryption may end up
producing more data than the input buffer due to compressed data. This
shows up especially with EAP-TNC that uses very compressible data format.
As a workaround, increase the decryption buffer length to (orig_len+500)*3.
This is a hack, but at least it handles most cases. TLS compression should
really be disabled for EAP use of TLS, but since this can show up with
common setups, it is better to handle this case.
If TNC is enabled, PEAPv0 server is now sending out SoH request to initiate
IF-TNCCS-SOH (Microsoft NAP / Statement of Health) handshake. The results
are currently only shown in debug log and they do not affect authentication
or authorization result.
It looks like Microsoft implementation does not match with their
specification as far as PRF+ label usage is concerned.. IPMK|CMK is derived
without null termination on the label, but the label for CSK derivation
must be null terminated.
This allows cryptobinding to be used with PEAPv0 in a way that
interoperates with Windows XP SP3 (RC2) and as such, this functionality is
now enabled as an optional addition to PEAPv0.
Microsoft uses reverse order for MS-MPPE keys in EAP-PEAP when compared to
EAP-FAST derivation of ISK. Swap the keys here to get the correct ISK for
EAP-PEAPv0 cryptobinding. This resolves the cryptobinding interop issue
with WinXP SP3 RC2. However, it looks like MSK derivation does not
interoperate when using cryptobinding, so this code remains disabled for
the time being.
This implementation is complete for PEAPv0 (Microsoft extension), but the
use of cryptobinding is disabled in this version, i.e., this does not
change protocol behavior at all.
Interop tests between hostapd and wpa_supplicant work fine, but there are
some problems in getting hostapd to interoperate with Windows XP SP3 RC2
(peer replies with Result Failure to the attempted cryptobinding). The
implementation will remain disabled until this issue has been resolved.
EAP-PEAP was the only method that used the external eap_tlv.c server
implementation. This worked fine just for the simple protected result
notification, but extending the TLV support for cryptobinding etc. is not
trivial with such separation. With the TLV processing integrated into
eap_peap.c, all the needed information is now available for using
additional TLVs.
Tunneled EAP sequence is now used to perform both the authentication (e.g.,
using EAP-GTC) and TNC validation (EAP-TNC) inside the EAP-FAST tunnel if
TNC has been enabled.
This adds EAP-TNC method and TNCS (IF-IMV and IF-TNCCS) functionality.
There is no integration with EAP-TTLS and EAP-FAST at this point, so this
version is not yet suitable for real use (i.e., EAP-TNC can only be tested
outside a tunnel which is not an allowed configuration for deployment).
However, the basic TNCS functionality is more or less complete and this
version seems to interoperate with wpa_supplicant.
Number of TLVs were processed in groups and these cases were now separated
into more flexible processing of one TLV at the time. wpabuf_concat()
function was added to make it easier to concatenate TLVs. EAP Sequences are
now supported in both server and peer code, but the server side is not
enabled by default.
This allows Phase 2 Identity Request to be skipped if the identity is
already known from PAC-Opaque received in TLS handshake in order to save
one roundtrip from normal authentication.
