It looks like [MS-PEAP] 3.2.5.6 points towards this being the expected
behavior (however, that chapter is very confusing).
In addition, remove Cryptobinding TLV from response if the received
Cryptobinding TLV is not valid. Add some more debug messages to the case
where the received Cryptobinding TLV is found invalid.
Process SoH Request in SoH EAP Extension method and reply with SoH TLV. The
contents of SSoH is not yet complete (i.e., some of the required attributes
are still missing). Use of SoH is disabled by default; it can be enabled
with tnc=soh in phase1 parameter for PEAP.
crypto_binding=# in phase1 network parameter can now be used to change the
PEAPv0 cryptobinding behavior (0 = do not use, 1 = optional (default),
2 = required).
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 peer
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.
