On Tue, 8 Aug 2023, Damien Miller wrote: > On Mon, 7 Aug 2023, Chris Rapier wrote: > > > > The broader issue of hiding all potential keystroke timing is not yet fixed. > > > > Could some level of obfuscation come from enabling Nagle for interactive > > sessions that has an associated TTY? Though that would be of limited > > usefulness in low RTT environments. I don't like the idea of having a steady > > drip of packets as that seems problematic both in terms of code complexity and > > network usage. I also don't like the idea of imposing random jitter though > > that might be easier to implement. However, without actual modeling I have no > > idea if that would actually improve things. > > Nagle is usually turned off because it causes annoying perceptions of > non-deterministic latency. > > For ssh, IMO sending interactive traffic on a fixed clock (e.g. every > 2-4ms) instead of as soon as possible, and adding fake keystroke packets > for some interval after the user stops generating traffic is the way to > fix it. I've slowly been preparing for this by reworking the mainloop and > associated timers. Here's the beginning of an implementation of this. Far from complete, but the timing quantisation part seems to work at least. https://github.com/djmdjm/openssh-wip/pull/24 -d _______________________________________________ openssh-unix-dev mailing list openssh-unix-dev@xxxxxxxxxxx https://lists.mindrot.org/mailman/listinfo/openssh-unix-dev
