Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Why does SSH send 100 packets per keystroke?

eieio.games

Post reply on HN
Print view View original

51–60 of 375 posts

Re: Why does SSH send 100 packets per keystroke?

#51

Post by Refreeze5224 »

PaulHoule wrote: post #37

I find it disturbing. One thing you notice if you have ADSL is that some services are built as if slower connections matter and others are not. Like Google's voice and audio chat services work poorly but most of the others work well. Uploading images to Mastodon, Bluesky, Facebook, LinkedIn, Instagram and Nextdoor is reliable, but for Tumblr you have to try it twice. I don't what they are doing wrong but they are doi…

You're not ok with a security/privacy tool using defensive techniques because of ... the lack of fiber in Africa?

Re: Why does SSH send 100 packets per keystroke?

#52

Post by Fnoord »

snowmobile wrote: post #2

> 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"

> Speaking of smoking guns

Oh shoot! A shooting.

So the TL;DR of this post is: don't change this setting unless you know what you're doing.

Re: Why does SSH send 100 packets per keystroke?

#53

Post by eieio »

kenmacd wrote: post #48

@eieio: whatever email protection you're running is triggering on the extension info. For example I see: > And they’re sent to servers that advertise the availability of the [email protected] extension. What if we just…don’t advertise [email protected]?

Is it possible that this is on your end?

The extension is "ping@openssh.com." It shows up in the blog reliably for me across several browsers and devices.

Re: Why does SSH send 100 packets per keystroke?

#54

Post by kevin_thibedeau »

snowmobile wrote: post #2

> 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"

Chastise it with a reminder that you're using smokeless powder.

Re: Why does SSH send 100 packets per keystroke?

#55

Post by gucci-on-fleek »

PaulHoule wrote: post #37

I find it disturbing. One thing you notice if you have ADSL is that some services are built as if slower connections matter and others are not. Like Google's voice and audio chat services work poorly but most of the others work well. Uploading images to Mastodon, Bluesky, Facebook, LinkedIn, Instagram and Nextdoor is reliable, but for Tumblr you have to try it twice. I don't what they are doing wrong but they are doi…

I agree with your general point that most companies/projects do a terrible job optimizing for slow computers/networks, but OpenSSH is from the OpenBSD people, who are well-known for supporting ancient hardware [0]. Picking a random architecture, they fully support a system with only 64MB of memory [1], and the base install includes SSH. So I suspect that OpenSSH is fairly well tested on crappy computers/networks.

[0]: https://www.openbsd.org/plat.html

[1]: https://www.openbsd.org/landisk.html#hardware

Re: Why does SSH send 100 packets per keystroke?

#56

Post by OneDeuxTriSeiGo »

eikenberry wrote: post #45
dathinab wrote: post #10

> Keystroke obfuscation can be disabled client-side. please never do that (in production) if anyone half way serious tries they _will_ be able to break you encryption end find what you typed this isn't a hypothetical niche case obfuscation mechanism, it's a people broke SSH then a fix was found case. I don't even know why you can disable it tbh.

It is to prevent timing attacks but there are many ssh use cases where it is 100% computer to computer communications where there is no key based timing attack possible.

There is an argument that if:

- you are listening to an SSH session between devices

- and you know what protocol is being talked over the connection (i.e. what they are talking about)

- and the protocol is reasonably predictable

then you gain enough information about the plaintext to start extracting information about the cipher and keys.

It's a non-trivial attack by all means but it's totally feasible. Especially if there's some amount of observable state about the participants being leaked by a third party source (i.e. other services hosted by the participants involved in the same protocol).

Re: Why does SSH send 100 packets per keystroke?

#57

Post by PhilipRoman »

eikenberry wrote: post #45
dathinab wrote: post #10

> Keystroke obfuscation can be disabled client-side. please never do that (in production) if anyone half way serious tries they _will_ be able to break you encryption end find what you typed this isn't a hypothetical niche case obfuscation mechanism, it's a people broke SSH then a fix was found case. I don't even know why you can disable it tbh.

It is to prevent timing attacks but there are many ssh use cases where it is 100% computer to computer communications where there is no key based timing attack possible.

I haven't given this more than 5 seconds of thought, but wouldn't it make sense to only enable the timing attack prevention for pseudo-terminal sessions (-t)?

Re: Why does SSH send 100 packets per keystroke?

#58

Post by rubslopes »

eieio wrote: post #20
snowmobile wrote: post #2

> 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"

Yes! While this post was written entirely by me, I wouldn't be surprised if I had "smoking gun" ready to go because I spent so much time debugging with Claude last night.

It's interesting how LLMs influence us, right? The opposite happened to me: I loved using em dashes, but AI ruined it for me.

Re: Why does SSH send 100 packets per keystroke?

#59

Post by calvinmorrison »

Terretta wrote: post #42
jcynix wrote: post #31

Earlier quoted context omitted.

It's what they read on The Internets when training, so don't expect them to generate new phrases, other than what they learned from it?

### The answer that fits everything (and what to do about it)

cant wait for chatgpt to make me read about grandmas secret recipe and scroll through 6 ads to see the ingredients for my chicken teriyaki dinner

Re: Why does SSH send 100 packets per keystroke?

#60

Post by andai »

rubslopes wrote: post #58
eieio wrote: post #20

Earlier quoted context omitted.

Yes! While this post was written entirely by me, I wouldn't be surprised if I had "smoking gun" ready to go because I spent so much time debugging with Claude last night.

It's interesting how LLMs influence us, right? The opposite happened to me: I loved using em dashes, but AI ruined it for me.

I still love using emdashes, and people already thought I was a robot!

https://xkcd.com/3126/

Soon the Andy 3000 will finally be a reality...

Post reply on HN