If the Confirm message is received from the server before the Identity
exchange has been completed, the group has not yet been determined and
data->grp is NULL. The error path in eap_pwd_perform_confirm_exchange()
did not take this corner case into account and could end up
dereferencing a NULL pointer and terminating the process if invalid
message sequence is received. (CVE-2015-5316)
Signed-off-by: Jouni Malinen <j@w1.fi>
All but the last fragment had their length checked against the remaining
room in the reassembly buffer. This allowed a suitably constructed last
fragment frame to try to add extra data that would go beyond the buffer.
The length validation code in wpabuf_put_data() prevents an actual
buffer write overflow from occurring, but this results in process
termination. (CVE-2015-5315)
Signed-off-by: Jouni Malinen <j@w1.fi>
The cleanup code will handle this, but it is more robust to make sure
this is cleared to zero when allocating a new buffer.
Signed-off-by: Jouni Malinen <j@w1.fi>
The L (Length) and M (More) flags needs to be cleared before deciding
whether the locally generated response requires fragmentation. This
fixes an issue where these flags from the server could have been invalid
for the following message. In some cases, this could have resulted in
triggering the wpabuf security check that would terminate the process
due to invalid buffer allocation.
Signed-off-by: Jouni Malinen <j@w1.fi>
The remaining number of bytes in the message could be smaller than the
Total-Length field size, so the length needs to be explicitly checked
prior to reading the field and decrementing the len variable. This could
have resulted in the remaining length becoming negative and interpreted
as a huge positive integer.
In addition, check that there is no already started fragment in progress
before allocating a new buffer for reassembling fragments. This avoid a
potential memory leak when processing invalid message.
Signed-off-by: Jouni Malinen <j@w1.fi>
The length of the received Commit and Confirm message payloads was not
checked before reading them. This could result in a buffer read
overflow when processing an invalid message.
Fix this by verifying that the payload is of expected length before
processing it. In addition, enforce correct state transition sequence to
make sure there is no unexpected behavior if receiving a Commit/Confirm
message before the previous exchanges have been completed.
Thanks to Kostya Kortchinsky of Google security team for discovering and
reporting this issue.
Signed-off-by: Jouni Malinen <j@w1.fi>
This extends EAP-pwd peer support to allow NtHash version of password
storage in addition to full plaintext password. In addition, this allows
the server to request hashed version even if the plaintext password is
available on the client. Furthermore, unsupported password preparation
requests are now rejected rather than allowing the authentication
attempt to continue.
Signed-off-by: Jouni Malinen <j@w1.fi>
This gets registered in tls_openssl.c from tls_init(), so there is no
need for EAP-pwd implementation to register explicitly. This avoids some
corner cases where OpenSSL resources do not get fully freed on exit.
Signed-off-by: Jouni Malinen <j@w1.fi>
Use an explicit memset call to clear any configuration parameter and
dynamic data that contains private information like keys or identity.
This brings in an additional layer of protection by reducing the length
of time this type of private data is kept in memory.
Signed-off-by: Jouni Malinen <j@w1.fi>
This makes the EAP-pwd server and peer implementations more robust
should OpenSSL fail to derive random number for some reason. While this
is unlikely to happen in practice, the implementation better be prepared
for this should something unexpected ever happen. See
http://jbp.io/2014/01/16/openssl-rand-api/#review-of-randbytes-callers
for more details.
Signed-off-by: Florent Daigniere <nextgens@freenetproject.org>
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: Florent Daigniere <nextgens@freenetproject.org>
This changes OpenSSL calls to explicitly clear the EC_POINT memory
allocations when freeing them. This adds an extra layer of security by
avoiding leaving potentially private keys into local memory after they
are not needed anymore. While some of these variables are not really
private (e.g., they are sent in clear anyway), the extra cost of
clearing them is not significant and it is simpler to just clear these
explicitly rather than review each possible code path to confirm where
this does not help.
Signed-off-by: Florent Daigniere <nextgens@freenetproject.org>
This changes OpenSSL calls to explicitly clear the bignum memory
allocations when freeing them. This adds an extra layer of security by
avoiding leaving potentially private keys into local memory after they
are not needed anymore. While some of these variables are not really
private (e.g., they are sent in clear anyway), the extra cost of
clearing them is not significant and it is simpler to just clear these
explicitly rather than review each possible code path to confirm where
this does not help.
Signed-off-by: Florent Daigniere <nextgens@freenetproject.org>
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>
Instead of using implicit limit based on 16-bit unsigned integer having
a maximum value of 65535, limit the maximum length of a fragmented
EAP-pwd message explicitly to 15000 bytes. None of the supported groups
use longer messages, so it is fine to reject any longer message without
even trying to reassemble it. This will hopefully also help in reducing
false warnings from static analyzers (CID 68124).
Signed-off-by: Jouni Malinen <j@w1.fi>
If invalid group was negotiated, compute_password_element() left some of
the data->grp pointer uninitialized and this could result in
segmentation fault when deinitializing the EAP method. Fix this by
explicitly clearing all the pointer with eap_zalloc(). In addition,
speed up EAP failure reporting in this type of error case by indicating
that the EAP method execution cannot continue anymore on the peer side
instead of waiting for a timeout.
Signed-off-by: Jouni Malinen <j@w1.fi>
This is somewhat of a corner case since there is no real point in using
so short a fragmentation threshold that it would result in this message
getting fragmented. Anyway, it is better be complete and support this
case as well.
Signed-off-by: Jouni Malinen <j@w1.fi>
If fragmentation is used, the temporary inbuf/outbuf could have been
leaked in error cases (e.g., reaching maximum number of roundtrips).
Signed-off-by: Jouni Malinen <j@w1.fi>
The standard fragment_size network parameter can now be used to
configure EAP-pwd fragmentation limit instead of always using the
hardcoded value of 1020.
Signed-hostap: Jouni Malinen <j@w1.fi>
At least some error paths (e.g., hitting the limit on hunt-and-peck
iterations) could have resulted in double-freeing of some memory
allocations. Avoid this by setting the pointers to NULL after they have
been freed instead of trying to free the data structure in a location
where some external references cannot be cleared. [Bug 453]
Signed-hostap: Jouni Malinen <j@w1.fi>
Remove the GPL notification text from EAP-pwd implementation per
approval from Dan Harkins who contributed these files.
(email from Dan Harkins <dharkins@lounge.org> dated
Wed, 4 Jan 2012 16:25:48 -0800)
Signed-hostap: Jouni Malinen <j@w1.fi>
This structure was not really used for anything apart from figuring out
length of the EAP-pwd header (and even that in a way that would not work
with fragmentation). Since the bitfields in the structure could have
been problematic depending on target endianness, remove this unnecessary
structure.
Signed-hostap: Jouni Malinen <j@w1.fi>
Another niceness of OpenSSL is that if the high-order bit of a 521-bit
big num is not set then BN_bn2bin() will just return 65 bytes instead of
66 bytes with the 1st (big endian, after all) being all zero. When this
happens the wrong number of octets are mixed into function H(). So
there's a whole bunch of "offset" computations and BN_bn2bin() dumps the
big number into a buffer + offset. That should be obvious in the patch
too.
The changes are:
1. the word "and" in the hunting-and-pecking string passed to the KDF
should be capitalized.
2. the primebitlen used in the KDF should be a short not an int.
3. the computation of MK in hostap is based on an older version of the
draft and is not the way it's specified in the RFC.
4. the group being passed into computation of the Commit was not in
network order.
