While the existing code already addresses TLS Message Length validation
for both EAP-TLS peer and server side, this adds explicit checks and
rejection of invalid messages in the functions handling reassembly. This
does not change externally observable behavior in case of EAP server.
For EAP peer, this starts rejecting invalid messages instead of
addressing them by reallocating the buffer (i.e., ignoring TLS Message
Length in practice).
Signed-hostap: Jouni Malinen <j@w1.fi>
This EAP type uses a vendor specific expanded EAP header to encapsulate
EAP-TLS with a configuration where the EAP server does not authenticate
the EAP peer. In other words, this method includes only server
authentication. The peer is configured with only the ca_cert parameter
(similarly to other TLS-based EAP methods). This method can be used for
cases where the network provides free access to anyone, but use of RSN
with a securely derived unique PMK for each station is desired.
The expanded EAP header uses the hostapd/wpa_supplicant vendor
code 39068 and vendor type 1 to identify the UNAUTH-TLS method.
Signed-hostap: Jouni Malinen <j@w1.fi>
Some deployed authentication servers seem to be unable to handle the TLS
Session Ticket extension (they are supposed to ignore unrecognized TLS
extensions, but end up rejecting the ClientHello instead). As a
workaround, disable use of TLS Sesson Ticket extension for EAP-TLS,
EAP-PEAP, and EAP-TTLS (EAP-FAST uses session ticket, so any server that
supports EAP-FAST does not need this workaround).
Signed-hostap: Jouni Malinen <j@w1.fi>
tls_disable_session_ticket=1 in phase1/phase2 can now be used to disable
use of TLS Session Ticket extension (which is enabled by default in
recent OpenSSL versions). This can be used to work around issues with
broken authentication servers that do not ignore unrecognized TLS
extensions properly.
Signed-hostap: Jouni Malinen <j@w1.fi>
Only allow the TLS library keying material exporter functionality to be
used for MSK derivation with TLS-based EAP methods to avoid exporting
internal TLS keys from the library.
Signed-hostap: Jouni Malinen <j@w1.fi>
OpenSSL wrapper was using the same certificate store for both Phase 1
and Phase 2 TLS exchange in case of EAP-PEAP/TLS, EAP-TTLS/TLS, and
EAP-FAST/TLS. This would be fine if the same CA certificates were used
in both phases, but does not work properly if different CA certificates
are used. Enforce full separation of TLS state between the phases by
using a separate TLS library context in EAP peer implementation.
Signed-hostap: Jouni Malinen <j@w1.fi>
Prepare for multiple TLS PRF functions by renaming the SHA1+MD5 based
TLS PRF function to more specific name and add tls_prf() within the
internal TLS implementation as a wrapper for this for now.
Signed-hostap: Jouni Malinen <j@w1.fi>
These protocols seem to be abandoned: latest IETF drafts have expired
years ago and it does not seem likely that EAP-TTLSv1 would be
deployed. The implementation in hostapd/wpa_supplicant was not complete
and not fully tested. In addition, the TLS/IA functionality was only
available when GnuTLS was used. Since GnuTLS removed this functionality
in 3.0.0, there is no available TLS/IA implementation in the latest
version of any supported TLS library.
Remove the EAP-TTLSv1 and TLS/IA implementation to clean up unwanted
complexity from hostapd and wpa_supplicant. In addition, this removes
any potential use of the GnuTLS extra library.
This function does not get called with in_data == NULL in practice, but
it seems to be at least partly prepared for that case, so better make it
consistent by handling the NULL value throughout the function.
Undocumented (at least for the time being) TLS parameters can now
be provided in wpa_supplicant configuration to enable some workarounds
for being able to connect insecurely to some networks. phase1 and
phase2 network parameters can use following options:
tls_allow_md5=1
- allow MD5 signature to be used (disabled by default with GnuTLS)
tls_disable_time_checks=1
- ignore certificate expiration time
For now, only the GnuTLS TLS wrapper implements support for these.
This converts tls_connection_handshake(),
tls_connection_server_handshake(), tls_connection_encrypt(), and
tls_connection_decrypt() to use struct wpa_buf to allow higher layer
code to be cleaned up with consistent struct wpabuf use.
In addition, start ordering header file includes to be in more
consistent order: system header files, src/utils, src/*, same
directory as the *.c file.
It looks like GnuTLS (at least newer versions) is using random padding
on the application data and the previously used 100 byte extra buffer
for tls_connection_encrypt() calls was not enough to handle all cases.
This resulted in semi-random authentication failures with EAP-PEAP and
EAP-TTLS during Phase 2.
Increase the extra space for encryption from 100 to 300 bytes and add an
error message into tls_gnutls.c to make it easier to notice this issue
should it ever show up again even with the larger buffer.
Previous version assumed that the Flags field is always present and
ended up reading one octet past the end of the buffer should the Flags
field be missing. The message length would also be set incorrectly
(size_t)-1 or (size_t)-5, but it looks like reassembly code ended up
failing in malloc before actually using this huge length to read data.
RFC 2716 uses a somewhat unclear description on what exactly is included
in the TLS Ack message ("no data" can refer to either Data field in 4.1
or TLS Data field in 4.2), so in theory, it would be possible for some
implementations to not include Flags field. However,
EAP-{PEAP,TTLS,FAST} need the Flags field in Ack messages, too, for
indicating the used version.
The EAP peer code will now accept the no-Flags case as an Ack message if
EAP workarounds are enabled (which is the default behavior). If
workarounds are disabled, the message without Flags field will be
rejected.
[Bug 292]
Windows Server 2008 NPS gets very confused if the TLS Message Length is
not included in the Phase 1 messages even if fragmentation is not used.
If the TLS Message Length field is not included in ClientHello message,
NPS seems to decide to use the ClientHello data (excluding first six
octets, i.e., EAP header, type, Flags) as the OuterTLVs data in
Cryptobinding Compound_MAC calculation (per PEAPv2; not MS-PEAP)..
Lets add the TLS Message Length to PEAPv0 Phase 1 messages to get rid of
this issue. This seems to fix Cryptobinding issues with NPS and PEAPv0
is now using optional Cryptobinding by default (again) since there are
no known interop issues with it anymore.
I fixed the engine issue in phase2 of EAP-TTLS. The problem was that you
only defined one engine variable, which was read already in phase1. I
defined some new variables:
engine2
engine2_id
pin2
and added support to read those in phase2 wheres all the engine
variables without number are only read in phase1. That solved it and I
am now able to use an engine also in EAP-TTLS phase2.
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.
