Bug fix for --nat-rand-port mode to ensure that the port to be
NAT'd is properly defined so that the fwknopd server will NAT
connnections to this port instead of applying the NAT operation to the
port that is to be accessed via -A. This change also prints the
randomly assigned port to stdout regardless of whether --verbose mode is
used (since it not then the user will have no idea which port is
actually going to be NAT'd on the fwknopd side).
[libfko] Added the ability to maintain backwards compatibility with the
now deprecated "zero padding" strategy in AES mode that was a hold over
from the old perl fwknop implementation. This enables the backwards
compatiblity tests to continue to pass in the test suite.
Added --enable-openssl-checks to send all SPA packets encrypted via libfko
through the OpenSSL library to ensure that the libfko usage of AES is always
compatible with OpenSSL. This ensures that the fwknop usage of AES is properly
implemented as verified by the OpenSSL library, which is a frequently audited
high profile crypto engine. If a vulnerability is discovered in OpenSSL and a
change is made, then the --enable-openssl-checks mode will allow the test suite
to discover this in a automated fashion for fwknop.
Significant bug fix to honor the full encryption key length for
user-supplied Rijndael keys > 16 bytes long. Previous to this bug fix,
only the first 16 bytes of a key were actually used in the encryption/
decryption process even if the supplied key was longer. The result was
a weakening of expected security for users that had keys > 16 bytes,
although this is probably not too common. Note that "passphrase" is
perhaps technically a better word for "user-supplied key" in this
context since Rijndael in CBC mode derives a real encryption/decryption
key from the passphrase through a series of applications of md5 against
the passphrase and a random salt. This issue was reported by Michael T.
Dean. Closes issue #18 on github.
Added chain_exists() check to SPA rule creation so that if any
of the fwknop chains are deleted out from under fwknopd they will be
recreated on the fly. This mitigates scenarios where fwknopd might be
started before a system level firewall policy is applied due to init
script ordering, or if an iptables policy is re-applied without
restarting fwknopd.
[client] (Franck Joncourt) Contributed a patch to allow the fwknop
client to be stopped during the password entry prompt with Ctrl-C before
any SPA packet is sent on the wire.
Added a new '--pcap-file <file>' option to allow pcap files to
be processed directly by fwknopd instead of sniffing an interface. This
feature is mostly intended for debugging purposes.
Added --disable-gpg to the autoconf ./configure script
via configure.ac. This makes it easy to not have fwknop/fwknopd
link against libgpgme even if it is installed on the local system.
The Debian hardening-includes package sets CFLAGS and LDFLAGS as follows for PIE support:
_HARDENED_PIE_CFLAGS := -fPIE
_HARDENED_PIE_LDFLAGS := -fPIE -pie
The configure.ac file has been updated to conform to the above.
Bug fix to check b64_decode() return value to ensure that
non-base64 encoded data is never used. Even though other validation
routines checked decoded results, it is important to discard invalid
data as early as possible. Note too that such invalid data would only
be provided to b64_decode() after proper decryption, so the client must
provide authentic SPA data.
[client+server] Applied patch from Franck Joncourt to remove unnecessary
chmod() call when creating client rc file and server replay cache file.
The permissions are now set appropriately via open(), and at the same
time this patch fixes a potential race condition since the previous code
used fopen() followed by chmod().
Added validation of NAT access strings in the various NAT modes in libfko.
This applies to both the client and server, and test suite support was added
as well.
Applied patch from Franck Joncourt to have the perl FKO module link
against libfko in the local directory (if it exists) so that it doesn't
have to have libfko completely installed in /usr/lib/. This allows the
test suite to run FKO tests without installing libfko.
Added the ability to the test suite to compile, install, and run some
basic tests against the perl FKO module.
- [client] Added '-P udpraw' to allow the client to send SPA packets over
UDP with a spoofed source IP address. This is in addition to the
original 'tcpraw' and 'icmp' protocols that also support a spoofed
source IP.
- [server] Bug fix to accept SPA packets over ICMP if the fwknop client
is executed with '-P icmp' and the user has the required privileges.
(Vlad Glagolev) Submitted a patch to fix command exec mode
under SPA message type validity test. Support for command exec mode was
also added to the test suite.
Applied patch from Vlad Glagolev to fix ndbm/gdbm usage when --disable-file-cache
is used for the autoconf configure script. This functionality was broken in
be4193d734850fe60f14a26b547525ea0b9ce1e9 through improper handling of #define
macros from --disable-file-cache.
Fernando Arnaboldi from IOActive found several conditions in
which the server did not properly throw out maliciously constructed
variables in the access.conf file. This has been fixed along with new
fuzzing tests in the test suite.
- [client+server] Fernando Arnaboldi from IOActive found that strict
filesystem permissions for various fwknop files are not verified. Added
warnings whenever permissions are not strict enough, and ensured that
files created by the fwknop client and server are only set to user
read/write.
- [client] Fernando Arnaboldi from IOActive found a local buffer overflow
in --last processing with a maliciously constructed ~/.fwknop.run file.
This has been fixed with proper validation of .fwknop.run arguments.
This commit fixes a condition in which the server did not properly validate
allow IP addresses from malicious authenticated clients. This has been fixed
with stronger allow IP validation.
- [server] Fernando Arnaboldi from IOActive found several DoS/code
execution vulnerabilities for malicious fwknop clients that manage to
get past the authentication stage (so a such a client must be in
possession of a valid access.conf encryption key). These vulnerbilities
manifested themselves in the handling of malformed access requests, and
both the fwknopd server code along with libfko now perform stronger input
validation of access request data. These vulnerabilities affect
pre-2.0.3 fwknop releases.
- [test suite] Added a new fuzzing capability to ensure proper server-side
input validation. Fuzzing data is constructed with modified fwknop
client code that is designed to emulate malicious behavior.
Updated the 'make install' step to not overwrite any existing config files in
/etc/fwknop/ and instead install new copies from the source tree at
/etc/fwknop/fwknopd.conf.inst and /etc/fwknop/access.conf.inst
Set restrictive permissions on /etc/fwknop/ directory and /etc/fwknop/* files.
Current default permissions on /etc/fwknop/ and /etc/fwknop/* are too lax.
Implemented a new check to ensure that the iptables 'comment' match exists to
ensure the proper environment for fwknopd operations. This check is controlled
by the new ENABLE_IPT_COMMENT_CHECK variable, and was suggested by Hank
Leininger.
For GPG mode, added a new access.conf variable "GPG_ALLOW_NO_PW" to make it
possible to leverage a server-side GPG key pair that has no associated
password. This comes in handy when a system requires the user to leverage
gpg-agent / pinentry which can present a problem in automated environments as
required by the fwknopd server. Now, it might seem like a problem to remove
the passphrase from a GPG key pair, but it's important to note that simply
doing this is little worse than storing the passphrase in the clear on disk
anyway in the access.conf file. Further, this link help provides additional
detail:
http://www.gnupg.org/faq/GnuPG-FAQ.html#how-can-i-use-gnupg-in-an-automated-environment
