Most protocols extracting keys from TLS use RFC 5705 exporters which is
commonly implemented in TLS libraries. This is the mechanism used by
EAP-TLS. (EAP-TLS actually predates RFC 5705, but RFC 5705 was defined
to be compatible with it.)
EAP-FAST, however, uses a legacy mechanism. It reuses the TLS internal
key block derivation and derives key material after the key block. This
is uncommon and a misuse of TLS internals, so not all TLS libraries
support this. Instead, we reimplement the PRF for the OpenSSL backend
and don't support it at all in the GnuTLS one.
Since these two are very different operations, split
tls_connection_prf() in two. tls_connection_export_key() implements the
standard RFC 5705 mechanism that we expect most TLS libraries to
support. tls_connection_get_eap_fast_key() implements the
EAP-FAST-specific legacy mechanism which may not be implemented on all
backends but is only used by EAP-FAST.
Signed-Off-By: David Benjamin <davidben@google.com>
This gets rid of a valgrind warning on uninitialized memory read in the
eap_proto_fast_errors test case where the result was used after the
failed sha1_t_prf() call.
Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>
Free the allocated structure in error cases to remove need for each EAP
method to handle the error cases separately. Each registration function
can simply do "return eap_peer_method_register(eap);" in the end of the
function.
Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>
This adds support for optional functionality to validate server
certificate chain in TLS-based EAP methods in an external program.
wpa_supplicant control interface is used to indicate when such
validation is needed and what the result of the external validation is.
This external validation can extend or replace the internal validation.
When ca_cert or ca_path parameter is set, the internal validation is
used. If these parameters are omitted, only the external validation is
used. It needs to be understood that leaving those parameters out will
disable most of the validation steps done with the TLS library and that
configuration is not really recommend.
By default, the external validation is not used. It can be enabled by
addingtls_ext_cert_check=1 into the network profile phase1 parameter.
When enabled, external validation is required through the CTRL-REQ/RSP
mechanism similarly to other EAP authentication parameters through the
control interface.
The request to perform external validation is indicated by the following
event:
CTRL-REQ-EXT_CERT_CHECK-<id>:External server certificate validation needed for SSID <ssid>
Before that event, the server certificate chain is provided with the
CTRL-EVENT-EAP-PEER-CERT events that include the cert=<hexdump>
parameter. depth=# indicates which certificate is in question (0 for the
server certificate, 1 for its issues, and so on).
The result of the external validation is provided with the following
command:
CTRL-RSP-EXT_CERT_CHECK-<id>:<good|bad>
It should be noted that this is currently enabled only for OpenSSL (and
BoringSSL/LibreSSL). Due to the constraints in the library API, the
validation result from external processing cannot be reported cleanly
with TLS alert. In other words, if the external validation reject the
server certificate chain, the pending TLS handshake is terminated
without sending more messages to the server.
Signed-off-by: Jouni Malinen <j@w1.fi>
It was possible to hit a NULL pointer dereference if Session-Id
derivation failed due to a memory allocation failure.
Signed-off-by: Jouni Malinen <j@w1.fi>
Reorder terms in a way that no invalid pointers are generated with
pos+len operations. end-pos is always defined (with a valid pos pointer)
while pos+len could end up pointing beyond the end pointer which would
be undefined behavior.
Signed-off-by: Jouni Malinen <j@w1.fi>
EAP-TLS was already doing this, but the other TLS-based EAP methods did
not mark methodState DONE and decision FAIL on local TLS processing
errors (instead, they left the connection waiting for a longer timeout).
Signed-off-by: Jouni Malinen <j@w1.fi>
If key derivation fails, there is no point in trying to continue
authentication. In theory, this could happen if memory allocation during
TLS PRF fails.
Signed-off-by: Jouni Malinen <j@w1.fi>
The EAP-TLS-based helper functions can easily use struct wpabuf in more
places, so continue cleanup in that direction by replacing separate
pointer and length arguments with a single struct wpabuf argument.
Signed-off-by: Jouni Malinen <j@w1.fi>
Reduce the amount of time keying material (MSK, EMSK, temporary private
data) remains in memory in EAP methods. This provides additional
protection should there be any issues that could expose process memory
to external observers.
Signed-off-by: Jouni Malinen <j@w1.fi>
This makes the implementation less likely to provide useful timing
information to potential attackers from comparisons of information
received from a remote device and private material known only by the
authorized devices.
Signed-off-by: Jouni Malinen <j@w1.fi>
Use size_t instead of int for storing and comparing the TLV length
against the remaining buffer length to make this easier for static
analyzers to understand.
Signed-off-by: Jouni Malinen <j@w1.fi>
This was previously checked through the eap_peer_tls_ssl_init() call
which made it difficult for static analyzers. Add an explicit check for
config == NULL into the beginnign of eap_fast_init() since this will
always result in initialization failing anyway.
Signed-off-by: Jouni Malinen <j@w1.fi>
Some EAP methods can go through a step that is expected to fail and as
such, should not trigger temporary network disabling when processing
EAP-Failure or deauthentication. EAP-WSC for WPS was already handled as
a special case, but similar behavior is needed for EAP-FAST with
unauthenticated provisioning.
Signed-hostap: Jouni Malinen <j@w1.fi>
EAP-FAST requires pac_file to be configured, so make it clearer from the
debug output if missing configuration parameter was the reason for
EAP-FAST initialization failing.
Signed-hostap: Jouni Malinen <j@w1.fi>
This adds a new getSessionId() callback for EAP peer methods to allow
EAP Session-Id to be derived. This commits implements this for EAP-FAST,
EAP-GPSK, EAP-IKEv2, EAP-PEAP, EAP-TLS, and EAP-TTLS.
Signed-hostap: Jouni Malinen <jouni@qca.qualcomm.com>
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>
data->phase2_method cannot really be NULL if
eap_fast_init_phase2_method() returns success, but this construction
seems to be too difficult for some static analyzers. While this change
is not really needed in practice, it makes it easier to go through
warnings from such analyzers.
Signed-hostap: Jouni Malinen <j@w1.fi>
While EAP-FAST uses protected success notification, RFC 5422, Section
3.5 points out a possibility of EAP-Failure being sent out even after
protected success notification in case of provisioning. Change the
EAP-FAST peer implementation to accept that exception to the protected
success notification. This allows the station to re-connect more quickly
to complete EAP-FAST connection in the case the server rejects the
initial attempt by only allowing it to use to provision a new PAC.
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.
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.
It looks like ACS did not like PAC Acknowledgment TLV before Result TLV, so
reorder the TLVs to match the order shown in a
draft-cam-winget-eap-fast-provisioning-09.txt example. This allows
authenticated provisioning to be terminated with Access-Accept (if ACS has
that option enabled). Previously, provisioning was otherwise successful,
but the server rejected connection due to not understanding the PAC Ack
("Invalid TEAP Data recieved").
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.
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.
