GNU Gatekeeper 5.15 released

 *** This is a security update ***

Download: https://www.gnugk.org/h323download.html

Serveral issues related to authentication features have been fixed.

Besides the security updates, another bug has been fix to respect the InternalNetworks setting when the ExternalIP setting is active.

 

Changes from 5.14 to 5.15
=========================
- BUGFIX(authenticators.cxx) small fixes to H235AuthDesECB and H235AuthDesCTS
- BUGFIX(ipauth.cxx) fix checking prefixes
- BUGFIX(sqlauth.cxx) don't accept empty passwords
- BUGFIX(gkauth.cxx) fix in Q.931 authentication
- BUGFIX(gkauth.cxx) fix auth cache expiry
- disable command execution for port notifications unless the feature is explicitely activated by ./configure --enable-port-notification-exec
- BUGFIX(GkStatus.cxx) improve ssh status port authentication
- BUGFIX(ProxyChannel.cxx) make sure we respect InternalNetworks= when using ExternalIP=

GNU Gatekeeper 5.14 released

 

GNU Gatekeeper version 5.14 has been released.

Download: https://www.gnugk.org/h323download.html

This is mostly a bug fixing release, but it also updates the Amazon AWS IP detection to the current standard.

Changes from 5.13 to 5.14
=========================
- update AWS IP detection to IMDSv2
- BUGFIX(RasTbl.h) fix potential memory leak
- BUGFIX(h323utils.cxx) fix detection of 'site local' and 'unique local' IPv6 addresses
- BUGFIX(Makefile.in) restore compatibility with GCC 4, 5 and 6
- BUGFIX(Toolkit.cxx) restore compatibility with very old versions of OpenSSL
- BUGFIX(h323utils.cxx) fix numeric overflow
- BUGFIX(Toolkit.cxx) fix iterator usage (found by Coverity)
 

 

GNU Gatekeeper 5.13 released

GNU Gatekeeper version 5.13 has been released.

Download: https://www.gnugk.org/h323download.html

This is a bug fix release with a no new features added. It fixes an issue with the RTP port detection and 2 other minor issues.

New release of PTLib

I have just bundeled up the changes and bug fixes of the past 2 years and released PTLib 2.10.9.6.

Most notable in this release is working IPv6 on *BSD, macOSX and Solaris as well as support for newer compilers and many small platform fixes.

Since PTLib is the foundation for the GNU Gatekeeper and many H323Plus projects, all these improvements get propagated into those projects as well.

Changes:
- IPv6 support fixed for *BSD, macOSX and Solaris
- support for newer compiler, eg. gcc 13 and VS2022
- support for C++-17
- support for Win64 builds
- support AIX as platform
- small OpenBSD fixes
- other small fixes

Download from https://www.h323plus.org/source/

GNU Gatekeeper 5.12 released

 GNU Gatekeeper version 5.12 has been released.

Download: https://www.gnugk.org/h323downldad.html

This is a bug fix release with a few new features added.

Another important bug in the handling of the ExternalIP switch has been fixed as well as Y2K38 issues.

This release also adds features:

• support for Oracle databases
• easier cloud deployment with IP detection with STUN
• better load scaling by mixing proxied with direct mode endpoints in a single gatekeeper
• Windows 64bit executables with VS2022

Full list of changes:

• enable more runtime hardening flags from OpenSSF recommendation 11/2023
• fix bug with H.245 address when using ExternalIP= switch without H.460.18/.19
• auto-detect public IP with ExternalIP=STUN and STUNServer=stun.example.com
• compiler support for VS2022
• new database driver for Oracle and new timestamp format 'Oracle'
• new switch [EP::xxx] ForceDirectMode=1 to handle all calls from this endpoint in direct mode
• BUGFIX(RasSrv.cxx, gkauth.cxx) make sure time_t is handled unsigned to avoid Y2K38 issue
• BUGFIX(ProxyChannel.cxx) check for too small packets when acting as encryption proxy

 

GNU Gatekeeper 5.11 released

GNU Gatekeeper version 5.11 has been released.

Download: https://www.gnugk.org/h323download.html

This is a bug fix release with a few new features added.

An important bug in the handling of the ExternalIP switch has been fixed.

We also added a few features that make it easier to use GnuGk with Graphana and InfluxDB monitoring.

Changes and additions:

• remove non-working command line switch -e / --externalip, use config file to set ExternalIP
• new accounting variables %{registrations}, %{calls}, %{total-calls}, %{successful-calls}, %{allocated-bandwidth}
• new switch [HttpAcct] Authorization= to send authorization headers to support InfluxDB
• replace \r and \n in HttpAcct body with carriage return and line feed characters
• new switch: [RasSrv::LRQFeatures] PreserveDestination=1 (helpful when calling Pexip servers)

GNU Gatekeeper 5.10 released

 

GNU Gatekeeper version 5.10 has been released.

Download: https://www.gnugk.org/h323download.html

This is a bug fix release.

Bugs fixed:

• fix a crash when handling the MasterSlaveDetermination message
  
• fix the documentation of [RasSrv::LRQFeatures] NeighborTimeout and consistently treat the value as 10th of a second in the program
  

GNU Gatekeeper 5.9 released

GNU Gatekeeper version 5.9 is out with a number of bug fixes and a few new features.

Download: https://www.gnugk.org/h323download.html

New features:

• new switches [Proxy] CachePortDetection=1 and CachePortDetectionDuration= to cache port detection packets for faster media connects when IgnoreSignaledIPs= is active
  
• new switch: [EP::] ForceTerminalType=
• new place holder for port notifications: %t for port type
• experimental: better error recovery if multiplexed RTP sending fails

Please note that Radius support is disabled by default now. You can enable it with the --enable-radius switch when running configure.

Bug fixes:

• fix bug in port detection with AllowSignaledIPsFrom=
• when DNS name resolves to IP without alias, remove alias from ACF completely (Cisco interop)
• remove RTP session 0 from internal tables once H.245 master has assigned a session ID
• fix compilation of Avaya support
• initialized cmsg struct to zero before using
• fix regression introduced with MatchH239SessionsByIDOnly= switch

GNU Gatekeeper 5.8 released

GNU Gatekeeper version 5.8 has been released with a number of bug fixes and a few new features.

To stay updated on new releases, please also follow us on Twitter!

Improved interoperability with:

• EdgeProtect
• Avaya
  

 New features:

• experimental support for Avaya's non-standard version of H.323 (./configure --enable-avaya) (thanks Konstantin Prokazov)
• consider RFC 6598 shared network space (100.64.0.0/10) and Zeroconf (169.254.0.0/16) as private IPs
  
• new switch [Proxy] AllowSignaledIPsFrom= to skip auto-detect for messages received directly from certain IPs when IgnoreSignaledIPs=1
• new switch [Proxy] AllowAnyRTPSourcePortForH239From= to handle incorrect RTCP addresses in H.239 OLC (EdgeProtect interop)
• new switch [RoutedMode] MatchH239SessionsByIDOnly= to never attempt to match a H.239 reverse channel by type for improved interoperability with EdgeProtect
• new switches to set the HTTP Content-Type header in HttpAcct, HttpPasswordAuth and Routing::Http
• new switch [Routing::Http] JSONResponse=1 to send more flexible routing data in the HTML reponses
• many new status port shortcuts (see manual section for details)

Bug fixes:

• fix H.460.18/.19 on multi-homed servers
• fix race condition when handling H.460.19 multiplex IDs
• fix media loop on half port-detected channel when media is very early
• fix Net-SNMP query for total bandwidth
• save RTCP address from OLC for port-detection
• always check AllowSignaledIPs= before applying IgnoreSignaledAllH239IPs or IgnoreSignaledPrivateH239IPs
• handle extensions and CSRC in RTP header with H.235 half-call media
• better endpointIDs on Windows when compiling without OpenSSL

GNU Gatekeeper 5.7 released

GNU Gatekeeper version 5.7 has some important bug fixes, improves interoperability
with other vendors and also has a few new features.
 

Several severe crashes and a few memory leaks have been fixed.

Improved interoperability with:

• Lifesize endpoints
• Poly's Microsoft Teams gateway
• Polycom RealPresence Capture Server

New features:

• You get a warning in the GUI / on the status port if one of your endpoints has an incorrect time setting and this password authentication fails. This makes trouble shooting a lot easier.
• Invalid TPKT packets (eg. due to network errors) now don't necessarily take down an otherwise healthy call. Use the new  AbortOnInvalidTPKT=0 switch to enable.
• GnuGk will now also return unused memory back to the OS periodically to make it available again to other applications on the same server.
  
• You have a new %{Vendor} variable for SqlAuth RegQuerys and LuaAuth

Full change log:

- BUGFIX(ProxyChannel.cxx) fix crash on non-standard H.245 Indication from
  Polycom RealPresence Capture Server
- BUGFIX(ProxyChannel.cxx) fix possible crashes on non-standard generic information in OLCs
- print warning message on status port when passwords get rejected due to wrong time
- BUGFIX(httpacct.cxx) fix memory leak
- BUGFIX(ProxyChannel.cxx) fix possible crash
- BUGFIX(gk.cxx) avoid crash when terminating in the middle of program startup,
  set non-zero exit code so restarter notices error
- return unused memory back to OS periodically
- new switch: [RoutedMode] AbortOnInvalidTPKT=0 for more graceful handling of network errors
- BUGFIX(gk.cxx) fix for running on Alpine Linux (needs updated PTLib, too)
- don't start GnuGk if RTP multiplexing is configured, but we can't start the listener
- new switch: [RoutedMode] MatchH239SessionsByType=0 to fix presentations with
  LifeSize endpoints over Poly's Microsoft Teams gateway
- BUGFIX(ProxyChannel.cxx) make sure we don't set RTP address on multiplexed RTCP keepalive
- BUGFIX(RasSrv.cxx) look at all tokens for H.235.TSSM
- add %{Vendor} variable for SqlAuth RegQuery and LuaAuth

New releases of H323Plus and PTLib

 H323Plus 1.27.2 and PTLib 2.10.9.4 have been released.

Changes in H323Plus:

- support for Alpine Linux for smaller container images
- crash fixed on invalid RTCP packets
- memory leaks fixed
- GetCrytoMasterKey() restored that got lost in 1.27.1
- better support for cross-compiling
- various updates for newer compilers
- some smaller bug fixes

https://www.h323plus.org/source/

 

Changes in PTLib:

- support for Alpine Linux
- better support for cross-compiling
- various smaller bug fixes

https://github.com/willamowius/ptlib/releases

H.323: IPv4 to IPv6 migration

Many networks are migrating from IPv4 to IPv6. What can you do if still have H.323 endpoints that only support IPv4 ?

The GNU Gatekeeper can translate IPv4 into IPv6 calls and vice versa.
You can use one GnuGk to IPv6 enable all of your existing IPv4 endpoints.

 

 

All you have to do is enable IPv6 in your configuration and GnuGk will automatically
detect the connection type of your endpoints and convert the call.

All it takes is one switch in your config:

[Gatekeeper::Main]
EnableIPv6=1 

Using the GNU Gatekeeper to create TLS tunnels

Most H.323 vendors did not implement encrypting the signaling connection with TLS. They only encrypt the media (RTP). But you can use the two GNU Gatekeepers to encrypt you call signaling even when your endpoints don't support this natively.

Suppose you have 2 locations and want to connect them securely over the public internet.

GnuGk can encrypt call signalling between those locations using TLS and encrypt the media (RTP) using H.235.6 (AES encryption). 

 Configuration for GNU Gatekeeper 1 (prefix 01)

 

[Gatekeeper::Main]

[RoutedMode]
GKRouted=1
H245Routed=1
CallSignalPort=1720
AcceptUnregisteredCalls=1
; make sure H.245 gets tunneled for TLS
H245TunnelingTranslation=1
; add AES media encryption if the endpoint doesn't encrypt itself
EnableH235HalfCallMedia=1
; only allow encrypted calls
RequireH235HalfCallMedia=1
; change the media key after 2^31 operations
EnableH235HalfCallMediaKeyUpdates=1

[Proxy]
Enable=1

[ModeSelection]
0.0.0.0/0=PROXY
; only use routed mode for local calls
192.168.0.0/18=H245ROUTED

[TLS]
EnableTLS=1
PrivateKey=/path/to/server.pem
Certificates=/path/to/server.pem
CAFile=/path/to/rootcert.pem
Passphrase=MySecret
CheckCertificateIP=1

[Gatekeeper::Auth]
FileIPAuth=required;Setup

[FileIPAuth]
; allow all calls from local network
192.168.1.0/24=allow
; only allow TLS encrypted and authenticated calls from elsewhere
any=onlyTLS

[RasSrv::PermanentEndpoints]
; the GnuGk in the other location, serving prefix 02
1.2.3.4:1300=remote-gw;02

[EP::remote-gw]
; use TLS to call remote GnuGk
UseTLS=1 

Configuration for GNU Gatekeeper 2 (prefix 02)

[Gatekeeper::Main]

[RoutedMode]
GKRouted=1
H245Routed=1
CallSignalPort=1720
AcceptUnregisteredCalls=1
; make sure H.245 gets tunneled for TLS
H245TunnelingTranslation=1
; add AES media encryption if the endpoint doesn't encrypt itself
EnableH235HalfCallMedia=1
; only allow encrypted calls
RequireH235HalfCallMedia=1
; change the media key after 2^31 operations
EnableH235HalfCallMediaKeyUpdates=1

[Proxy]
Enable=1

[ModeSelection]
0.0.0.0/0=PROXY
; only use routed mode for local calls
192.168.0.0/18=H245ROUTED

[TLS]
EnableTLS=1
PrivateKey=/path/to/server.pem
Certificates=/path/to/server.pem
CAFile=/path/to/rootcert.pem
Passphrase=MySecret
CheckCertificateIP=1

[Gatekeeper::Auth]
FileIPAuth=required;Setup

[FileIPAuth]
; allow all calls from local network
192.168.1.0/24=allow
; only allow TLS encrypted and authenticated calls from elsewhere
any=onlyTLS

[RasSrv::PermanentEndpoints]
; the GnuGk in the other location, serving prefix 01
1.2.3.5:1300=remote-gw;01

[EP::remote-gw]
; use TLS to call remote GnuGk
UseTLS=1 

Other options

You could also configure the remote GNU Gatekeeper as a neighbor, but beware that the RAS traffic between neighbors will show meta data (whois is caling who) in clear text! 

See the GnuGk manual section on TLS for more details and examples how to generate the OpenSSL certificates. 

 

Using TCP Keepalive to Detect Network Errors

This is not only a H.323 topic, but since H.323 also uses TCP connections, it applies to H.323 as well:

To detect network errors and signaling connection problems, you can enable TCP keep alive feature. It will increase signaling bandwidth used, but as bandwidth utilized by signaling channels is low from its nature, the increase should not be significant. Moreover, you can control it using keep alive timeout.

The problem is that most system use keep alive timeout of 7200 seconds, which means the system is notified about a dead connection after 2 hours. You probably want this time to be shorter, like one minute or so. On each operating system, the adjustment is done in a different way.

After settings all parameters, it's recommended to check whether the feature works correctly - just make a test call and unplug a network cable at either side of the call. Then see if the call terminates after the configured timeout.

Linux systems

Use sysctl -A to get a list of available kernel variables
and grep this list for net.ipv4 settings (sysctl -A | grep net.ipv4).
There should exist the following variables:

net.ipv4.tcp_keepalive_time:   time of connection inactivity after which
                               the first keep alive request is sent
net.ipv4.tcp_keepalive_probes: number of keep alive requests retransmitted
                               before the connection is considered broken
net.ipv4.tcp_keepalive_intvl:  time interval between keep alive probes

You can manipulate with these settings using the following command:

sysctl -w net.ipv4.tcp_keepalive_time=60 net.ipv4.tcp_keepalive_probes=3 \

    net.ipv4.tcp_keepalive_intvl=10

This sample command changes TCP keepalive timeout to 60 seconds with 3 probes,
10 seconds gap between each. With this, your application will detect dead TCP
connections after 90 seconds (60 + 10 + 10 + 10).

FreeBSD and MacOS X

For the list of available TCP settings (FreeBSD 4.8 an up and 5.4):

sysctl -A | grep net.inet.tcp

net.inet.tcp.keepidle - Amount of time, in milliseconds, that the (TCP) 
connection must be idle before keepalive probes (if enabled) are sent.

net.inet.tcp.keepintvl - The interval, in milliseconds, between 
keepalive probes sent to remote machines. After TCPTV_KEEPCNT (default 
8) probes are sent, with no response, the (TCP)connection is dropped.

net.inet.tcp.always_keepalive - Assume that SO_KEEPALIVE is set on all 
TCP connections, the kernel will periodically send a packet to the 
remote host to verify the connection is still up.

therefore formula to calculate maximum TCP inactive connection time is 
following:

net.inet.tcp.keepidle + (net.inet.tcp.keepintvl x 8)

the result is in milliseconds.

therefore, by setting
net.inet.tcp.keepidle = 10000
net.inet.tcp.keepintvl = 5000
net.inet.tcp.always_keepalive =1 (must be 1 always)

the system will disconnect a call when TCP connection is dead for:
10000 + (5000 x 8) = 50000 msec (50 sec)

To make system remember these settings at startup, you should add them 
to /etc/sysctl.conf file

Solaris

For the list of available TCP settings:

ndd /dev/tcp \?

Keepalive related variables:
- tcp_keepalive_interval - idle timeout

Example:
ndd -set /dev/tcp tcp_keepalive_interval 60000

Windows 2000 and Windows NT

Search Knowledge Base for article ID 120642:
http://support.microsoft.com/kb/120642/EN-US

Basically, you need to tweak some registry entries under
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters

GNU Gatekeeper 5.6 released

Today GNU Gatekeeper version 5.6 has  been released.

Download: https://www.gnugk.org/h323download.html

It contains an important bug fix to H.460.19 multiplexing and H.460.26 (media over TCP) when using GnuGk's internal call forwarding (ForwadOnFacility).

I have also added an interop tweak to be able to call video services that don't understand H.323 URL aliases (eg. videobutler.nl). You can enable it with

[Routing::SRV]

ConvertURLs=1

Here is the full changelog:

• new switch: [Routing::SRV] ConvertURLs=1 to convert URL_IDs into H323_IDs
• BUGFIX(ProxyChannel.cxx) fix RTP multiplexing and H.460.26 when ForwardOnFacility is used
• BUGFIX(ProxyChannel.cxx) remove H.460.19 feature from Setup when using ForwardOnFacility=1
• new switch: [Gatekeeper::Main] GrantAllBRQ=1 to accept any BRQ, even if the conferenceID is invalid

GNU Gatekeeper 5.5. released

I am happy to announce the release of GNU Gatekeeper 5.5.

This release has new features and bug fixes when you run clustered gatekeepers. It also improves the port detection feature and we have a complete and up to date Chinese documentation.

You can download it from https://www.gnugk.org/h323download.html

New features:

• new feature GnuGkAssignedGatekeeper to push endpoints back to their intended home gatekeepers in the cluster, even if the endpoints don't support assigned gatekeepers
• support new PBKDF2 password hashes for ssh logins to the status port
• new switches to fine tune port detection for H.239 channels (IgnoreSignaledPublicH239IPsFrom=x and IgnoreSignaledAllH239IPs=1)
• new Chinese manual

Bug fixes:

• select correct source IP for neighbor pings
• set altGKisPermanent=true when redirecting endpoints
• fix RRJ to include alternates when RedirectGK=Endpoints limit is reached
• fix reading of AllowSignaledIPs= switch
• don't complain about [Neighbor::xxx] SendAliases switch when using--strict

Enjoy!

GNU Gatekeeper 5.4 released

I am happy to announce the release of GNU Gatekeeper 5.4.

You can download it from https://www.gnugk.org/h323download.html

New features:

• new accounting module to send accounting data to an MQTT server
• support for redis as database (eg. as backend for password storage)

Bug fixes:

• important fix for H.245 tunneling translation with H.460.18 endpoints
• fix for snmpwalk in PTLib-SNMP implementation
• fix sending alternate gatekeeper list to endpoints with assigned gatekeeper
• improved DRQ from child gatekeepers
• fix TLS with neighbor gatekeeper

Please also note that a bug has been found in PTLib that can cause a crash in any GnuGk version if you use the status port (manually of from an application). Please upgrade to PTLib 2.10.9.3!

Howto block H.323 spam calls with fail2ban

When you run the GNU Gatekeeper, you can block spam calls from the well known bots ("MERA RU", "SimpleOPAL" etc.) eg. using a small LUA script in your config.

But that alone doesn't stop the load on the server, because often these bots keep on making calls.

Fail2ban to the rescue!

With this filter definition in /etc/fail2ban/filter.d/gnugk.conf you can check fro rejected calls:

[Definition]
failregex = Dropping call CRV=[0-9]+ from <HOST>:[0-9]+ due to Setup authentication failure
ignoreregex =


And then you can add this jail definition to /etc/fail2ban/jail.local to block the IP:

[gnugk]
enabled  = true
logpath  = /var/log/gnugk.log
filter   = gnugk
bantime  = 6000
maxretry = 2
action   = iptables[name=GnuGk, port=1720, protocol=tcp]


Voila!

GNU Gatekeeper 5.3 released

I have just released GNU Gatekeeper version 5.3.

You can download it from https://www.gnugk.org/h323download.html

This release has a number of new features as well as some important bug
fixes.

Whats new ?

• LRQ loop detection to optimize calls flows between multiple neighbor gatekeepers This new feature has the potential to significantly reduce the load on all gatekeepers and prevent "LRQ storms".
• new routing policy to set call destinations by querying HTTP or REST servers, see [Routing::Http]
• much improved support for SNMP
• important bug fix for TLS encryption of signaling channels
• important bug fixes for H.460.18 NAT traversal (for H.245 tunneling and for multi-homed servers)
• performance optimization: this version can handle 5-10% more proxied  calls on the same hardware
• performance optimization: re-authenticate lightweight, additive registrations only when new aliases differ. This significantly reduces the load on password databases.

Enjoy!


Full change log:

- BUGFIX(ProxyChannel.cxx) don't send H.245 address to tunneling
  H.460.18 endpoint, breaks call when H.245 multiplexing
- performance optimization: 5% faster UDP handling
- changed default: [SNMP] Implementation=PTlib
- remove unfinished Windows-SNMP implementation, use PTLib-SNMP on Windows
- support SET and GET-NEXT in PTLib-SNMP
- support SNMP sysUpTime when running as standalone agent
- BUGFIX(configure.in) LARGE_FDSET defaults to off
- new SNMP OID 1.3.6.1.4.1.27938.11.1.9 to query total bandwidth allocated to ongoing calls
- BUGFIX(ProxyChannel.cxx) fix hangup when making many TLS calls quickly one after another
- BUGFIX(RasSrv.cxx) don't require H.460.22 parameters in ARQs
- BUGFIX(ProxyChannel.cxx) fix TLS without LARGE_FDSET
- BUGFIX(ProxyChannel.cxx) don't send H.460.22 priority field in SCI
- BUGFIX(gkauth.cxx) free memory from cached and expired passwords
- re-authenticate lightweight, additive registrations only when new aliases differ
- remove switch [Proxy]DisableRTPQueueing, always disabled now
- new routing policy: http with config section [Routing::Http]
- BUGFIX(ProxyChannel.cxx) fix H.460.18 on multi-homed servers (SCI comes from the correct IP now)
- new switch to disable SNMP traps [SNMP] EnableTraps=0
- BUGFIX(ProxyChannel.cxx) don't throw SNMP trap on H.245 connection errors
  (causes crash under load with Net-SNMP)
- BUGFIX(snmp.cxx) shutdown GnuGk when SNMP agent can't be started
- BUGFIX(snmp.cxx) protect NetSNMP library calls with mutex
- changed default: ForwardResponse now defaults to 1 in [RasSrv::LRQFeatures] and [Neighbor::...]
- new feature: loop detection for LRQs [RasSrv::LRQFeatures] LoopDetection=1
- BUGFIX(Neighbor.cxx) some settings in [RasSrv::LRQFeatures] were ignored if not set in [Neighbor::...]

Celebrating 20 Years of GnuGk

20 years ago, in June 1999, I released the first version of the GNU Gatekeeper. Back then we still called it "OpenH323 Gatekeeper".

The first version was very simple and only supported RAS and what we call 'direct mode' today, but it still seems useful to people and within a year it grew into a tool that people used in production.

I quit my day job in 2003 to work full time on GnuGk and it has feed the family ever since. I am still amazed how well it works to give software away for free. How many people and companies contribute and give feedback and how many are willing to pay for support or new
features.

I want to thank everybody who used it, provided feedback, bug fixes and ideas to make it into the great software that it is today!

We are not stopping here, the next release is already underway with many improvements and new features. Watch for it!

Happy Birthday GnuGk!