New in version 4.0
==================
Enhancements
------------
* Add support for Network Time Security (NTS) authentication
* Add support for AES-CMAC keys (AES128, AES256) with Nettle
* Add authselectmode directive to control selection of unauthenticated sources
* Add binddevice, bindacqdevice, bindcmddevice directives
* Add confdir directive to better support fragmented configuration
* Add sourcedir directive and "reload sources" command to support dynamic
NTP sources specified in files
* Add clockprecision directive
* Add dscp directive to set Differentiated Services Code Point (DSCP)
* Add -L option to limit log messages by severity
* Add -p option to print whole configuration with included files
* Add -U option to allow start under non-root user
* Allow maxsamples to be set to 1 for faster update with -q/-Q option
* Avoid replacing NTP sources with sources that have unreachable address
* Improve pools to repeat name resolution to get "maxsources" sources
* Improve source selection with trusted sources
* Improve NTP loop test to prevent synchronisation to itself
* Repeat iburst when NTP source is switched from offline state to online
* Update clock synchronisation status and leap status more frequently
* Update seccomp filter
* Add "add pool" command
* Add "reset sources" command to drop all measurements
* Add authdata command to print details about NTP authentication
* Add selectdata command to print details about source selection
* Add -N option and sourcename command to print original names of sources
* Add -a option to some commands to print also unresolved sources
* Add -k, -p, -r options to clients command to select, limit, reset data
Bug fixes
---------
* Don't set interface for NTP responses to allow asymmetric routing
* Handle RTCs that don't support interrupts
* Respond to command requests with correct address on multihomed hosts
Removed features
----------------
* Drop support for RIPEMD keys (RMD128, RMD160, RMD256, RMD320)
* Drop support for long (non-standard) MACs in NTPv4 packets (chrony 2.x
clients using non-MD5/SHA1 keys need to use option "version 3")
* Drop support for line editing with GNU Readline
Changes:
19 Sep 2018: chrony-3.4 released
Enhancements
Add filter option to server/pool/peer directive
Add minsamples and maxsamples options to hwtimestamp directive
Add support for faster frequency adjustments in Linux 4.19
Change default pidfile to /var/run/chrony/chronyd.pid to allow chronyd without root privileges to remove it on exit
Disable sub-second polling intervals for distant NTP sources
Extend range of supported sub-second polling intervals
Get/set IPv4 destination/source address of NTP packets on FreeBSD
Make burst options and command useful with short polling intervals
Modify auto_offline option to activate when sending request failed
Respond from interface that received NTP request if possible
Add onoffline command to switch between online and offline state according to current system network configuration
Improve example NetworkManager dispatcher script
Bug fixes
Avoid waiting in Linux getrandom system call
Fix PPS support on FreeBSD and NetBSD
4 Apr 2018: chrony-3.3 released
Enhancements
Add burst option to server/pool directive
Add stratum and tai options to refclock directive
Add support for Nettle crypto library
Add workaround for missing kernel receive timestamps on Linux
Wait for late hardware transmit timestamps
Improve source selection with unreachable sources
Improve protection against replay attacks on symmetric mode
Allow PHC refclock to use socket in /var/run/chrony
Add shutdown command to stop chronyd
Simplify format of response to manual list command
Improve handling of unknown responses in chronyc
Bug fixes
Respond to NTPv1 client requests with zero mode
Fix -x option to not require CAP_SYS_TIME under non-root user
Fix acquisitionport directive to work with privilege separation
Fix handling of socket errors on Linux to avoid high CPU usage
Fix chronyc to not get stuck in infinite loop after clock step
15 Sep 2017: chrony-3.2 released
Enhancements
Improve stability with NTP sources and reference clocks
Improve stability with hardware timestamping
Improve support for NTP interleaved modes
Control frequency of system clock on macOS 10.13 and later
Set TAI-UTC offset of system clock with leapsectz directive
Minimise data in client requests to improve privacy
Allow transmit-only hardware timestamping
Add support for new timestamping options introduced in Linux 4.13
Add root delay, root dispersion and maximum error to tracking log
Add mindelay and asymmetry options to server/peer/pool directive
Add extpps option to PHC refclock to timestamp external PPS signal
Add pps option to refclock directive to treat any refclock as PPS
Add width option to refclock directive to filter wrong pulse edges
Add rxfilter option to hwtimestamp directive
Add -x option to disable control of system clock
Add -l option to log to specified file instead of syslog
Allow multiple command-line options to be specified together
Allow starting without root privileges with -Q option
Update seccomp filter for new glibc versions
Dump history on exit by default with dumpdir directive
Use hardening compiler options by default
Bug fixes
Don’t drop PHC samples with low-resolution system clock
Ignore outliers in PHC tracking, RTC tracking, manual input
Increase polling interval when peer is not responding
Exit with error message when include directive fails
Don’t allow slash after hostname in allow/deny directive/command
Try to connect to all addresses in chronyc before giving up
31 Jan 2017: chrony-3.1 released
Enhancements
Add support for precise cross timestamping of PHC on Linux
Add minpoll, precision, nocrossts options to hwtimestamp directive
Add rawmeasurements option to log directive and modify measurements option to log only valid measurements from synchronised sources
Allow sub-second polling interval with NTP sources
Bug fixes
Fix time smoothing in interleaved mode
16 Jan 2017: chrony-3.0 released
Enhancements
Add support for software and hardware timestamping on Linux
Add support for client/server and symmetric interleaved modes
Add support for MS-SNTP authentication in Samba
Add support for truncated MACs in NTPv4 packets
Estimate and correct for asymmetric network jitter
Increase default minsamples and polltarget to improve stability with very low jitter
Add maxjitter directive to limit source selection by jitter
Add offset option to server/pool/peer directive
Add maxlockage option to refclock directive
Add -t option to chronyd to exit after specified time
Add partial protection against replay attacks on symmetric mode
Don’t reset polling interval when switching sources to online state
Allow rate limiting with very short intervals
Improve maximum server throughput on Linux and NetBSD
Remove dump files after start
Add tab-completion to chronyc with libedit/readline
Add ntpdata command to print details about NTP measurements
Allow all source options to be set in add server/peer command
Indicate truncated addresses/hostnames in chronyc output
Print reference IDs as hexadecimal numbers to avoid confusion with IPv4 addresses
Bug fixes
Fix crash with disabled asynchronous name resolving
21 Nov 2016: chrony-2.4.1 released
Bug fixes
Fix processing of kernel timestamps on non-Linux systems
Fix crash with smoothtime directive
Fix validation of refclock sample times
Fix parsing of refclock directive
7 Jun 2016: chrony-2.4 released
Enhancements
Add orphan option to local directive for orphan mode compatible with ntpd
Add distance option to local directive to set activation threshold (1 second by default)
Add maxdrift directive to set maximum allowed drift of system clock
Try to replace NTP sources exceeding maximum distance
Randomise source replacement to avoid getting stuck with bad sources
Randomise selection of sources from pools on start
Ignore reference timestamp as ntpd doesn’t always set it correctly
Modify tracking report to use same values as seen by NTP clients
Add -c option to chronyc to write reports in CSV format
Provide detailed manual pages
Bug fixes
Fix SOCK refclock to work correctly when not specified as last refclock
Fix initstepslew and -q/-Q options to accept time from own NTP clients
Fix authentication with keys using 512-bit hash functions
Fix crash on exit when multiple signals are received
Fix conversion of very small floating-point numbers in command packets
Removed features
Drop documentation in Texinfo format
16 Feb 2016: chrony-2.3 released
Enhancements
Add support for NTP and command response rate limiting
Add support for dropping root privileges on Mac OS X, FreeBSD, Solaris
Add require and trust options for source selection
Enable logchange by default (1 second threshold)
Set RTC on Mac OS X with rtcsync directive
Allow binding to NTP port after dropping root privileges on NetBSD
Drop CAP_NET_BIND_SERVICE capability on Linux when NTP port is disabled
Resolve names in separate process when seccomp filter is enabled
Replace old records in client log when memory limit is reached
Don’t reveal local time and synchronisation state in client packets
Don’t keep client sockets open for longer than necessary
Ignore poll in KoD RATE packets as ntpd doesn’t always set it correctly
Warn when using keys shorter than 80 bits
Add keygen command to generate random keys easily
Add serverstats command to report NTP and command packet statistics
Bug fixes
Fix clock correction after making step on Mac OS X
Fix building on Solaris
20 Jan 2016: chrony-2.2.1 and chrony-1.31.2 released
Security fixes
Restrict authentication of NTP server/peer to specified key (CVE-2016-1567)
CVE-2016-1567: Impersonation between authenticated peers
When a server/peer was specified with a key number to enable authentication with a symmetric key, packets received from the server/peer were accepted if they were authenticated with any of the keys contained in the key file and not just the specified key.
This allowed an attacker who knew one key of a client/peer to modify packets from its servers/peers that were authenticated with other keys in a man-in-the-middle (MITM) attack. For example, in a network where each NTP association had a separate key and all hosts had only keys they needed, a client of a server could not attack other clients of the server, but it could attack the server and also attack its own clients (i.e. modify packets from other servers).
To not allow the server/peer to be authenticated with other keys, the authentication test was extended to check if the key ID in the received packet is equal to the configured key number. As a consequence, it’s no longer possible to authenticate two peers to each other with two different keys, both peers have to be configured to use the same key.
This issue was discovered by Matt Street of Cisco ASIG.
19 Oct 2015: chrony-2.2 released
Enhancements
Add support for configuration and monitoring over Unix domain socket (accessible by root or chrony user when root privileges are dropped)
Add support for system call filtering with seccomp on Linux (experimental)
Add support for dropping root privileges on NetBSD
Control frequency of system clock on FreeBSD, NetBSD, Solaris
Add system leap second handling mode on FreeBSD, NetBSD, Solaris
Add dynamic drift removal on Mac OS X
Add support for setting real-time priority on Mac OS X
Add maxdistance directive to limit source selection by root distance (3 seconds by default)
Add refresh command to get new addresses of NTP sources
Allow wildcard patterns in include directive
Restore time from driftfile with -s option if later than RTC time
Add configure option to set default hwclockfile
Add -d option to chronyc to enable debug messages
Allow multiple addresses to be specified for chronyc with -h option and reconnect when no valid reply is received
Make check interval in waitsync command configurable
Bug fixes
Fix building on NetBSD, Solaris
Restore time from driftfile with -s option if reading RTC failed
Removed features
Drop support for authentication with command key (run-time configuration is now allowed only for local users that can access the Unix domain socket)
23 Jun 2015: chrony-2.1.1 released
Bug fixes
Fix clock stepping by integer number of seconds on Linux
22 Jun 2015: chrony-2.1 released
Enhancements
Add support for Mac OS X
Try to replace unreachable and falseticker servers/peers specified by name like pool sources
Add leaponly option to smoothtime directive to allow synchronised leap smear between multiple servers
Use specific reference ID when smoothing served time
Add smoothing command to report time smoothing status
Add smoothtime command to activate or reset time smoothing
Bug fixes
Fix crash in source selection with preferred sources
Fix resetting of time smoothing
Include packet precision in peer dispersion
Fix crash in chronyc on invalid command syntax
27 Apr 2015: chrony-2.0 released
Enhancements
Update to NTP version 4 (RFC 5905)
Add pool directive to specify pool of NTP servers
Add leapsecmode directive to select how to correct clock for leap second
Add smoothtime directive to smooth served time and enable leap smear
Add minsources directive to set required number of selectable sources
Add minsamples and maxsamples options for all sources
Add tempcomp configuration with list of points
Allow unlimited number of NTP sources, refclocks and keys
Allow unreachable sources to remain selected
Improve source selection
Handle offline sources as unreachable
Open NTP server port only when necessary (client access is allowed by allow directive/command or peer/broadcast is configured)
Change default bindcmdaddress to loopback address
Change default maxdelay to 3 seconds
Change default stratumweight to 0.001
Update adjtimex synchronisation status
Use system headers for adjtimex
Check for memory allocation errors
Reduce memory usage
Add configure options to compile without NTP, cmdmon, refclock support
Extend makestep command to set automatic clock stepping
Bug fixes
Add sanity checks for time and frequency offset
Don’t report synchronised status during leap second
Don’t combine reference clocks with close NTP sources
Fix accepting requests from configured sources
Fix initial fallback drift setting
since 1.29 see file NEWS in the distfile.
Security fixes since 1.29:
* Modify chronyc protocol to prevent amplification attacks (CVE-2014-0021)
(incompatible with previous protocol version, chronyc supports both)
* Protect authenticated symmetric NTP associations against DoS attacks
(CVE-2015-1799)
* Fix access configuration with subnet size indivisible by 4 (CVE-2015-1821)
* Fix initialization of reply slots for authenticated commands (CVE-2015-1822)
since 1.24 see file NEWS in the distfile.
Security fixes since 1.24:
* Fix crash when processing crafted commands (CVE-2012-4502)
(possible with IP addresses allowed by cmdallow and localhost)
* Don't send uninitialized data in SUBNETS_ACCESSED and CLIENT_ACCESSES
replies (CVE-2012-4503) (not used by chronyc)
Reviewed by: Joerg Sonnenberger <joerg@netbsd.org>
The changes in version 1.24 are
Security fixes
--------------
* Don't reply to invalid cmdmon packets (CVE-2010-0292)
* Limit client log memory size (CVE-2010-0293)
* Limit rate of syslog messages (CVE-2010-0294)
Bug fixes/Enhancements
----------------------
* Support for reference clocks (SHM, SOCK, PPS drivers)
* IPv6 support
* Linux capabilities support (to drop root privileges)
* Memory locking support on Linux
* Real-time scheduler support on Linux
* Leap second support on Linux
* Support for editline library
* Support for new Linux readonly adjtime
* NTP client support for KoD RATE
* Read kernel timestamps for received NTP packets
* Reply to NTP requests with correct address on multihomed hosts
* Retry name resolving after temporary failure
* Fix makestep command, make it available on all systems
* Add makestep directive for automatic clock stepping
* Don't require _bigadj kernel symbol on NetBSD
* Avoid blocking read in Linux RTC driver
* Support for Linux on S/390 and PowerPC
* Fix various bugs on 64-bit systems
* Fix valgrind errors and compiler warnings
* Improve configure to support common options and variables
* Improve status checking and printing in chronyc
* Return non-zero exit code on errors in chronyc
* Reduce request timeout in chronyc
* Print estimated offset in sourcestats
* Changed chronyc protocol, incompatible with older versions
Reviewed by: Joerg Sonnenberger <joerg@netbsd.org>
The changes in version 1.23 are
* Support for MIPS, x86_64, sparc, alpha, arm, FreeBSD
* Fix serious sign-extension error in handling IP addresses
* RTC support can be excluded at compile time
* Make sources gcc-4 compatible
* Fix various compiler warnings
* Handle fluctuations in peer distance better.
* Fixed handling of stratum zero.
* Fix various problems for 64-bit systems
* Flush chronyc output streams after each command, to allow it to be
driven through pipes
* Manpage improvements
The changes in version 1.21 are
* Don't include Linux kernel header files any longer : allows chrony to
compile on recent distros.
* Stop trying to use RTC if continuous streams of error messages would
occur (Linux with HPET).
- Many small tidy-ups and security improvements.
- Merge support for 64bit architectures.
- Generate more informative syslog messages before exiting on failed
assertions.
- Fix bugs in clamping code for the tick value used when slewing a large
offset.
