SFTP support for subsecond times

[Mingye Wang (Artoria2e5)]

On 5/25/2023 8:28 PM, Daja / Dahya / Mark Dominik Bürkle wrote:
> using "synchronized" subsecond timestamps imho only makes sense with synchronized time (ntp) through that ssh tunnel, too.

This is not quite the case.

Assuming your goal of ntp-through-ssh is to have time sync: It is very 
easy for modern-day implementations of NTP to achieve sub-second 
precision: as simple as openntpd is (and as large as this NTP precision 
flame war gets), it gets things right to 2 ms in its competitor chrony's 
test, when network connection is permanent and jitter is 10 ms. Even in 
the worst intermittent case, it is correct to hundreds of milliseconds. 
As the table will tell you. And other implementations can do much better.[1]

[1]: https://chrony.tuxfamily.org/comparison.html

Assuming your goal of ntp-through-ssh is security: RFC 8915 NTS is a thing.

Regards,
Mingye Wang