Add "nocerttimecheck" directive to specify the number of clock updates
that need to be made before the time validation of certificates is
enabled. This makes NTS usable on machines that don't have a RTC.
If ntsrotate is set to 0, don't generate new server keys and don't save
them to ntsdumpdir. This allows the keys to be managed externally and
shared with other servers.
When replacing an NTP source, update the NTS address before the NTP
address to save cookies with the old NTP address instead of the newly
resolved address (which may immediately change to an address provided by
NTS-KE).
Include in the key dump file an identifier, the AEAD number, and the
age of the last key to improve robustness and avoid generating a new key
immediately on start.
Also, improve the code that saves and loads the file.
Save the NTS context and cookies to files in the NTS dumpdir when the
client NTS instances are destroyed or the address is changed, and reload
the data to avoid unnecessary NTS-KE requests when chronyd is restarted
or it is switching between different addresses resolved from the NTS-KE
or NTP name.
Add a context structure for the algorithm and keys established by
NTS-KE. Modify the client to save the context and reset the SIV key to
the C2S/S2C key before each request/response instead of keeping two SIV
instances.
This will make it easier for the server to support different algorithms
and allow the client to save the context with cookies to disk.
Make the NTS-KE retry interval exponentially increasing, using a factor
provided by the NKE session. Use shorter intervals when the server is
refusing TCP connections or the connection is closed or timing out
before the TLS handshake.
The server session instances are reused for different clients. Separate
the server name from the label used in log messages and set it on each
start of the session.
When a source was replaced and the new source had the same slot as the
old source, a wrong message was logged. Fix the condition to distinguish
correctly between changed address and port.
Fixes: 9468fd4aa6 ("ntp: allow changing port of source")
Improve the check to work with the actual timestamp of the leap second
instead of the closest midnight and don't turn it off on the leap
timeout. Also allow sample times to be checked in addition to the system
time and NTP time to avoid accumulation of samples mixing pre-leap and
post-leap timestamps (causing error of +/-0.5 or +/-1.0 seconds).
Don't require the caller to provide a SCK_Message (on stack). Modify the
SCK_ReceiveMessage*() functions to return a pointer to static buffers,
as the message buffer which SCK_Message points to already is.
On Linux, enable the SO_REUSEPORT option on sockets bound to a port in
order to support load balancing with multiple chronyd instances
(configured to not adjust the system clock).
The IP_FREEBIND option already allowed different instances to bind to
the same address and port, but only one was actually receiving packets.
As the instances don't share their state, sharing the NTP port doesn't
work well with the interleaved mode, symmetric mode, and rate limiting.
Sharing the NTS-KE port will not work until the server keys can be
derived from a shared key.
Earlier versions of macOS do not provide clock_gettime(). This patch
checks for clock_gettime() at run-time and falls back to gettimeofday()
if the symbol is not present.
Update the local clock errors with each update of the leap status to
avoid the kernel marking the clock as unsynchronized when a large
number of NTP samples is dropped.
When a leap second status is updated by a source, don't wait for the
next source selection and full update of the reference. Count votes from
sources that passed the previous selection and update the reference leap
status directly.
This should allow leap seconds to spread quickly even when the
samples are dropped or delayed by the filters.
Remove leap status from the NTP sample and set it independently from
the sample accumulation in order to accept a leap second sooner when
samples are filtered.
The reset command drops all measurements and switches the reference to
the unsynchronised state. This command can help chronyd with recovery
when the measurements are known to be no longer valid or accurate, e.g.
due to moving the computer to a different network, or resuming the
computer from a low-power state (which resets the system clock).
