This should really be upstreamed as an option on the ssh library. Its good to default to sending chaff in untrusted environments, but there are plenty of places where we might as well save the bandwidth
Why does SSH send 100 packets per keystroke?
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Re: Why does SSH send 100 packets per keystroke?
#12I mean, for modern version of Openssh it's not exactly wrong. The failure was to tell you why that is the normal behavior.
Re: Why does SSH send 100 packets per keystroke?
#13You can also use TCP_CORK to reduce the number of packets without any increased latency. Disabling TCP_NODELAY would also reduce number of packets + be portable & simpler to implement - but would incur a latency penalty.
I am aware of TCP_NODELAY (funny enough I recently posted about TCP_NODELAY to HN[1] when I was thinking about it for the same game that I wrote about here). But I think the latency hit from disabling it just doesn't work for me.
Re: Why does SSH send 100 packets per keystroke?
#14WAT. Please no.
Re: Why does SSH send 100 packets per keystroke?
#15Another good trick for debugging ssh's exact behavior is patching in "None" cipher support for your test environment. It's about the same work as trying to set up a proxy but lets you see the raw content of the packets like it was telnet.
For terminal games where security does not matter but performance and scale does, just offering telnet in the first place can also be worth consideration.
Re: Why does SSH send 100 packets per keystroke?
#16> That 20ms is a smoking gun - it lines up perfectly with the mysterious pattern we saw earlier! Speaking of smoking guns, anybody else reckon Claude overuses that term a lot? Seems anytime I give it some debugging question, it'll claim some random thing like a version number or whatever, is a "smoking gun"
Maybe it has something to do with your profile/memories?
Re: Why does SSH send 100 packets per keystroke?
#17I enjoyed this write up as it touched on several topics I enjoy reading about. Also I was unfamiliar with SSH being vulnerable in the past to keystroke timing!
2023 discussion about it here.
Re: Why does SSH send 100 packets per keystroke?
#18> That 20ms is a smoking gun - it lines up perfectly with the mysterious pattern we saw earlier! Speaking of smoking guns, anybody else reckon Claude overuses that term a lot? Seems anytime I give it some debugging question, it'll claim some random thing like a version number or whatever, is a "smoking gun"
ChatGPT too. And "lines up perfectly" when it doesnt actually line up with anything
Re: Why does SSH send 100 packets per keystroke?
#19> That 20ms is a smoking gun - it lines up perfectly with the mysterious pattern we saw earlier! Speaking of smoking guns, anybody else reckon Claude overuses that term a lot? Seems anytime I give it some debugging question, it'll claim some random thing like a version number or whatever, is a "smoking gun"
ChatGPT too. And "lines up perfectly" when it doesnt actually line up with anything
Re: Why does SSH send 100 packets per keystroke?
#20> That 20ms is a smoking gun - it lines up perfectly with the mysterious pattern we saw earlier! Speaking of smoking guns, anybody else reckon Claude overuses that term a lot? Seems anytime I give it some debugging question, it'll claim some random thing like a version number or whatever, is a "smoking gun"