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Comment by bitwize | Hacker News Reader

So uh, why did you design X in such a manner that any client could sniff any other client's events and windows by default, and only later add a (quite inadequate) SECURITY extension?

This is what we mean when we say that the security model of X is obsolete, and an afterthought besides. The threat model was completely different back then: every griefer, troll, thief, and state actor didn't have a pipe straight into your X session through the browser, and for the most part X was used to talk to trusted programs on trusted hosts.

Wayland, by contrast, has a security model for the modern, hostile internet built in from the start.

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> Wayland, by contrast, has a security model for the modern, hostile internet built in from the start.

And yet basic video and screen capture is not working for years now. Arbitrary rectangle capture still doesn't work on Ubuntu 16.04 in any tool I know of.

So they made it so secure to make basic features not work.

I wonder if there will be a successor to Wayland and X11 that learns from the mistakes of both?

Can't always make wise improvements if you don't first make awful mistakes that weren't properly considered in practice.

> I wonder if there will be a successor to Wayland and X11 that learns from the mistakes of both?

Ubuntu wanted to do this with Mir. The rest is history...

A pity that the Mir devs didn't really have any experience or deep knowledge of the Linux graphics stack...

It took the X11 devs, many of whom were also involved in Mesa and Linux graphics development, literally years just to get all of the necessary plumbing in place in order to replace what X11 was previously doing.

These developments help not only X11 or Wayland, but make the development of a newer, superior protocol to X11 and Wayland much easier, because the hard yards have been done for them.

It also makes it easier for those who might want to transition from Wayland to a hypothetical superior protocol.

> And yet basic video and screen capture is not working for years now. Arbitrary rectangle capture still doesn't work on Ubuntu 16.04 in any tool I know of.

I'm curious, what tools have you tried? I ask because the default screenshot tool works perfectly for stills (including stills of video playing in a window or full-screen), and the few video screen recording tools I've tried all worked perfectly. At the moment I'm using Kazam on 16.04 with the default Nouveau drivers, and a quick test with Chromium playing a video stream + Totem simultaneously playing a local video file confirms that everything is captured no problem. Full screen, arbitrary windows, all tested and working.

Tl;dr try Kazam, unless I'm misunderstanding the issue you describe?

> any client could sniff any other client's events and windows

That's a feature that I have used many times in the past. Isolation should be handled at the X server level, where it can be handled without excessive complexity or require breaking backward compatibility.

> default

Locked down defaults and enabling features opt-in is good design. (Principle of Least Privilege)

> Wayland

Isn't compatible as it's missing required features (by design).

BTW, i think SECURITY was to be a first step towards a more secure X. But nobody enabled it because it broke some big name programs (Firefox being one, supposedly)...

Because all programs were running under the same user account, so there was no use trying to build a security boundary between them in the X server.

Wanting to run mutually distrustful sandboxed apps side by side was not a popular use case back then.

Actually, that's not the case. Back then, it was much more commonplace to have a workstation and run local programs side by side with programs running on remote hardware. The network transparency of the X protocol was an advantage -- again, as long as you were running trusted programs on trusted remote hosts.

These days network transparency is a) irrelevant for most use cases and b) much better implemented with newer protocols like RDP and PCoIP. That's why it was removed from Wayland.

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