David Jacobs
- Suggested IP/network lists in SOURCE definitions
- Wording fixes in fwknop(8) manpage.
- Assisted in fwknop-1.9.2 testing.
Brian Snipes
- Wrote a graphical front-end for fwknop called "fwknopFE":
http://www.snipes.org/index.php?page=fwknopFE
- Found bug with legacy fingerprinting file "posf".
Joel Loudermilk
- Submitted patch to optionally disable email alerting. The end result
was the addition of the REPORT_METHOD keyword in fwknop.conf.
Blair Zajac
- Submitted patch to not install perl modules in /usr/lib/fwknop/ that
are already installed in the system perl lib tree.
- Submitted patch to use getpwuid() instead of just getlogin().
- Submitted patch to fix bug in install.pl and how the ~/lib directory
is created in client install mode.
- Found bug with perl module file paths and naming convention (this bug
resulted in some modules being needlessly installed).
- Suggested that fwknop handle rotated log files (even pcap logs get
rotated on some systems).
- Suggested that modules only required in server mode are not use at
runtime when running fwknop in client mode.
- Suggested -O optimization in Makefile.
- Found bug where log rotation detection would break under the size
change detection method. The result was the inode check in 0.9.6.
- Found bug where some Linux distributions have /var/run as type tmpfs,
and this caused fwknopd to die because it couldn't write to its PID
file.
- Suggested command path update code in install.pl so that the user does
not always have to edit the fwknop.conf and knopwatchd.conf files if
the system does not have commands in the default locations.
Will McCracken
- Reported bug on OS X where getlogin() does not return the correct
data. This permitted fwknop to be updated to fall back to ENV{'USER'}
var.
Omar A. Herrera
- Submitted a patch to fix a timeout bug in knoptm that caused newly
created rules to be deleted too quickly.
Werner Wiethege
- Submitted a patch to fix a bug in knoptm where inappropriate hash
keys were being deleted and so previous timeouts would apply to the
current interval.
Ronald Bister
- Submitted a fix for not being able to parse ifconfig output correctly
when languages besides English are used.
Hank Leininger
- Suggested privilege separation to minimize code that executes as root.
- Suggested NULL password GPG keys.
- Suggested integration with ssh-agent and gpg-agent.
Dwayne Rightler
- Submitted patch to fix bug where whatismyip.com altered their return
data format and this broke the -w command line switch.
Sebastien Jeanquier
- Contributed more rigorous regular expression for matching an IP address.
- Suggested allowing symmetric keys to exceed 256 bits.
- Suggested using Crypt::Random for random number generation.
- Suggested the integration of time synchronization as an additional
measure for the fwknopd daemon to validate incoming SPA packets (this
will probably be enabled by default).
- Suggested a new method of interacting with iptables to redirect
connections to one port to another port on the same system.
- Suggested making the --Spoof-user argument useable by non-root users.
- Suggested the ability to randomize a spoofed IP address.
- Suggested building in compatibility with external IP resolution sites
such as http://www.whatismyip.com/
- Provided a Mac OS X system to develop fwknop support for OS X. Many
thanks!
- Helped with the testing process for fwknop-1.8.2 and OS X support.
- Suggested the integration of SHA256 for replay attack detection.
- Suggested the OPEN_PORTS fix to not open ports that are not
specifically requested in an SPA packet.
- Noticed the bug where the "keep-state" option was not noticed when
checking for state tracking rules in ipfw policies.
Mate Wierdl
- Contributed patch (originally for the psad project) for building the
RPM on x86_64 platforms.
Raul Siles
- Bug report to allow OPEN_PORTS to be omitted in access.conf in favor of
having only PERMIT_CLIENT_PORTS enabled.
Leland Weathers
- Submitted patch to allow the GPG_REMOTE_ID variable to have the value
"ANY" to allow arbitrary gpg signing keys to match the SOURCE block.
Juuso Alasuutar
- Suggested that the install.pl script offer a mode where the user is not
prompted at all in order to make it easier to integrate fwknop with
the Source Mage Linux distribution. The result is the --Defaults option
to the install.pl script.
- Suggested the ability to use gpg keys without passwords.
Neal Baer
- Tested the fwknop-1.8 release for Windows systems (running Cygwin).
- Tested the cd_rpmbuilder script on SuSE systems.
Graham Clark
- Suggested man page documentation bug fixes.
Roy Segovia
- Submitted patch to fix print statement bug in command mode where the
command was inappropriately prepended with the source IP address.
- Reported bug with running fwknop under Cygwin on Windows 2003 Server,
which reports 'Gygwin' under the 'uname -o' output.
Mark Van De Vyver
- Reported a bug where the iptables command path was not being properly
discovered if it did not reside at the default location specified in the
fwknop.conf file.
- Submitted various documentation issues with the fwknop man pages. The -D
option in fwknop-1.8.2 resulted from this feedback.
- Reported a bug where the .xsession.errors file would fill with output
logged by fwknop when null passwords were read from stdin.
Flavio Machado
- Reported command mode bug where the source IP address is not properly
communicated to the SPA server.
Eggert Ehmke
- Reported resolution bug with http://www.whatismyip.com/. The result was
the interpretation of the link designed for automated scripts:
http://www.whatismyip.com/automation/n09230945.asp
Luis Martin Garcia
- Suggested using http://www.whatismyip.org/ instead of
http://www.whatismyip.com/
Gerry Reno
- Reported legacy knopwatchd.conf file in RPM package in fwknop-1.8.2.
Sean Greven
- Submitted patch for enhanced 'fwknopd --debug' output to include raw hex
dumps of SPA packet data before and after attempted decryption
operation. This allows the integration of cipher implementations other
than Crypt::Rijndael or GnuPG ciphers to be validated.
- Contributed a UI written in Delphi that runs on Windows platforms and
builds its own SPA packets without using the fwknop client. This is an
important development, since it proves that third-party UI integration
is possible.
Franck Joncourt
- Performed analysis of locale settings and suggested using the LC_ALL
environmental variable instead of the LANG variable (which is superseded
by LC_* vars).
- Created Debian packages for the IPTables::ChainMgr and IPTables::Parse
modules.
- Reported bug for distributing old knopmd.conf and knopspoof files.
- Submitted documentation patches for fwknop man pages.
- Submitted man pages for fwknop_serv and knoptm. Also submitted a patch
for the knoptm man page to discuss all command line options.
- Architected the process of packaging fwknop for the Debian Linux
distribution.
- Suggested 0600 permissions mode on all <proc>.pid files in
/var/run/fwknop/
- Suggested removing the Net::IPv4Addr dependency in the fwknop client
and in the knoptm daemon since functions from this module were never
actually used.
- Bug fix to make sure to apply BLACKLIST checks to IP addresses specified
with -a (or derived via -R) in addition to the source IP in the IP
header (which can be modified via --Spoof-src).
- Bug fix for check_commands() to ensure that proper include/exclude
criteria for incoming hash refs is performed.
- Suggested the --Override-config command line argument on the fwknopd
command line so that normal config variables from the
/etc/fwknop/fwknop.conf file can be superseded with values from the
specified file(s). Multiple files can be given as a comma-separated
list. Submitted patch to fix --Override-config parsing in knoptm.
Bug fix to add -O command line arg to knopwatchd to specify an override
config file if one is given on the fwknopd command line.
- Added the ability to send mail with the sendmail command in knopwatchd
One of the mailCmd and sendmailcmd must be available in fwknop.conf.
- Submitted patch to update the knopwatchd man page for the latest command
line options for 1.9.11.
Jose Luis Bellido
- Provided testing support for fwknop running on systems with Spanish
locale settings, and validated fwknop GnuPG communications.
Marius Rugan
- Suggested the ability to add firewall accept rules to the iptables
OUTPUT chain.
Grant Ferley
- Submitted patch to handle SIGCHLD in IPTables::ChainMgr.
- Submitted patch to handle Linux "cooked" interfaces for packet capture
(e.g. rp-pppoe interfaces).
The SPAPICT Team
- The SPAPICT Team consists of the following people:
Ambar Seksena (advisor)
Nippun Goel (advisor)
Abhishek Rahirikar (developer)
Aaditya Badve (developer)
Saurabh Jain (developer)
Satyajit Deshpande (developer)
- Submitted patch to implement client-defined firewall access timeouts.
- Submitted patch to implement SHA1 digests in SPA messages.
- Made various suggestions for the implementation of important fwknop
extensions, such as the integration architecture with Kerberos.
John Brendler
- Made a post to a Gentoo forum entitled "Single-Packet Authentication
(Crypt-Port-Knocking) in BASH". In this post John demonstrated that SPA
packets can be sent over random ports, and this suggestion is now
implemented in fwknop-1.9.4 in two forms: the --rand-port option, which
sends the SPA packet itself over a random UDP port, and --NAT-rand-port
which selects a random port encrypted within an SPA packet that is used
by the fwknopd server to forward connections over.
Kevin Hilton
- Suggested making the init script position as "99" instead of "20" on
Ubuntu systems.
Jean-Denis Girard
- Suggested that the "C" locale be set by default so that gpg process
output would always be correctly interpreted.
Mirek Trmac
- Contributed patches to allow fwknop to be bundled with Fedora. These
patches included the following, and all were sponsored by Red Hat:
Updates to fwknopd to remove the NetPacket module as a dependency
(this is a particularly important update since it assists with getting
fwknop bundled with Debian as well). The patch manually decodes the
network and transport layer headers.
A patch to make the fwknop init script not start fwknopd by default
on Red Hat systems. This patch also supports Fedora init script
conventions better (i.e. fwknop instead of the fwknopd name for the lock
file in /var/lock/subsys).
Updated the fwknop Makefile to respect the OPTS variable which is used
in the RPM spec file.
Bugfix in fwknop_serv to support the variable expansion code from
fwknopd. This was important for the TCPSERV_PID_FILE file which is
defined as $FWKNOP_RUN_DIR/fwknop_serv.pid.
Updated fwknopd to use the Net::Pcap API valid in Net::Pcap 0.14 for
the datalink() function (used to detect the datalink layer type).
Mike Holzmann
- Diagnosed a bug where SPA packets encrypted with 2048-bit keys would
exceed 1500 bytes if the 'encrypt-to' option was set in the default
~/.gnupg/options file. The result was the addition of the
--gpg-no-options command line argument on the fwknop command line, and
the GPG_NO_OPTIONS variable in the access.conf file for the fwknopd
daemon.
- Reported lots of 'Premature end of base64 data' and 'Premature padding
of base64 data' warning messages. A fix was applied to fwknopd to apply
more rigorous checks for base64 encoded characters, and either of the
two messages above will result in the packet data being discarded before
it is sent through any decryption function.
- Suggested documentation fixes in the fwknop(8) man page.
- Reported a bug where sniffing on ppp interface resulted in fwknopd not
being able to properly decode the IP header. The result was adding the
ENABLE_COOKED_INTF variable in the fwknop.conf file.
Francois Marier
- Submitted bug report for 2048-bits GnuPG keys that led to a bugfix and
the implementation of --gpg-use-options and the GPG_USE_OPTIONS variable
in the access.conf file.
- Helpful troubleshooting and testing on the Debian and Ubuntu Linux
distributions, and reviewed Debian packaging efforts.
Alexander Perlis
- Suggested a comprehensive ability to interface with third party software
after receiving valid SPA packet data. This is allows fwknop to easily
integrate with software that is already managing a firewall policy.
- Reported a bug in symmetric key mode where the fwknop client would not
place the terminal out of 'noecho' mode if a password less than 8
characters long is provided.
- Reported a bug in the EXTERNAL_* feature where SPA packets without a
list of ports specified on the command line would not be honored by the
fwknopd daemon.
- Reported a bug in the EXTERNAL_* feature where using --fw-list when
FIREWALL_TYPE is set to 'external_cmd' resulted in starting the fwknopd
daemons.
- Suggested the usage of the sendmail binary as the default for sendmail
email alerts instead of the mail binary.
Damien Stuart
- Wrote the first viable C implementation of fwknop called "libfko" (to be
released in a future version beyond the 1.9.10 release). This is a major
contribution and will allow SPA to be extended to secure systems where
perl is not even installed, or embedded systems (such as small routers
running OpenWRT) where perl cannot reasonably be deployed.
- Wrote the FKO perl module, which is an XS extension of the libfko C
functions.
- Found a bug where the number of SPA packet fields expected by fwknopd
did not allow client timeouts in the forward and local NAT modes.
Ted Drivas
- Reported a bug in properly decoding SPA packets sent over spoofed ICMP
packets. This bug was fixed by increasing the minimum expected ICMP
header length to 8 bytes.
Martin Ferrari
- Bug fix to provide a work around for fwknopd segfaults on Debian
systems when the version of Net::Pcap that is installed comes from doing
'apt-get install fwknop-server'. See the thread at
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=508432 for more info.
Julien Picalaus
- Contributed patches to implement a proper interface to
use ipfw 'sets' on systems running ipfw firewalls. This involved
changes to fwknopd, knoptm, and the fwknop.conf file like so:
Added a test to see if the local ipfw firewall policy is using dynamic
rules. Added ipfw_move_rule() so that rules can be moved from one set to
another. Added ipfw_disable() set subroutine and it is called at init for
IPFW_SET_NUM (except when ipfw isn't using dynamic rules). Made sure
that rule finding includes disabled rules (ipfw list -S and changes to
regexp) and returning the set in addition to the rule number. When
granting access, if a corresponding disabled rule already exists, enable
it instead of adding a new one (except when ipfw isn't using dynamic
rules). When adding rules, only use keep-state if there are already
dynamic rules. Added IPFW_SET_NUM so that the set number for new ipfw
can be specified, and add IPFW_DYNAMIC_INTERVAL so that the interval
over which rules that have no associated dynamic rules are removed (the
default is 60 seconds).
Jens Binnewies
- Reported an error condition where interfaces that are created and then
deleted and recreated would cause the fwknopd daemon to not be able to
sniff SPA packets. The typical example where this is important is with
ppp interfaces associated with VPN's that are shut down and recreated.
Martin Tan
- Submitted a patch to allow rules added by fwknopd to not be expired if
there are any established connections involving a source IP and a list of
ports. Once the established connections are removed, then any rules
added by fwknopd are then allowed to also be removed. This feature is
controlled by three new configuration variables in the fwknop.conf file:
ENABLE_CONNTRACK_PERSIST, CONNTRACK_ESTAB_PORTS, and IPT_CONNTRACK_FILE.
Jonathan Bennett
- Submitted patch to the fwknop client to add HTTP proxy support when
sending SPA packets over HTTP. The result is a new --HTTP-proxy option
that expects the proxy host to be given as "http://HOST", and it also
supports the "http://HOST:PORT" notation as well.
